Operating Systems and Networks
Operating Systems and Networks CIS 350
Popular in Course
Popular in Science
This 231 page Class Notes was uploaded by Sarai Morar on Monday September 21, 2015. The Class Notes belongs to CIS 350 at Colorado State University taught by Daniel Turk in Fall. Since its upload, it has received 62 views. For similar materials see /class/210150/cis-350-colorado-state-university in Science at Colorado State University.
Reviews for Operating Systems and Networks
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/21/15
Summary of Basic Linux Commands amp Concepts Concepts Disk partition Filesystem Directory amp subdirectory Home directory Shell Current working directory Root directory amp Path absolute vs relative Command syntax stdin stdout amp stderr Pipe vertical bar File permissions amp modes Commands ssh cat chmod ping exit nano umask traceroute passwd VI netstat who touch man more ps Ifconfig date less grep cal head cut tar pwd tail I o tr 0 zip Cd mkd39r sort compress Is rmdir df Cp uniq gznp sudo fdisk mv WC rm I n man man passwd man cat then n man headtail then n man sudo man In man cp info coreutils In invocation sort From within bin Is ahi sort n b k77 Is ahi sort n b k7174 k7677 k79710 shell programming n0 S for in Is source Cc do n n 1 D echo quotSn Si done S iUNIXLinux A Brief History Outline History of UNIXLinux Philosophy of UNIXLinux Structure of UNIX Linux Two UNIX Versions Because of the historical development of UNIX two versions developed First ATampT System V Then in parallel Berkeley BSD By the late 19805 these two different and somewhat incompatible versions of UNIX were in widespread use UNIX Like Systems In a new trend UNIXlike operating systems began to appear MINIX by Andrew Tanenbaum used a microkernel design with only 1600 lines of C and 800 lines of assembler in its first version In 1991 a Finnish student named Linus Torvalds released another UNIX clone named Linux version 001 Linux 5 Linux is a monolithic design rather than a microkernel design 9000 lines of C and 1000 of assembler Linux quickly grew in size and functionality Version 1 shipped in 1994 contained about 165000 lines of code Version 2 in 1996 contained about 470000 lines of C and 8000 lines of assembler Currently kernel 26 g Linux i An unusual feature of Linux is its business model it is free software and open source It can be downloaded for free from various Internet sites Users may use copy modify and redistribute the binary and source code freely However all works derived from the kernel may not be sold or redistributed in binary form only the source code must be made available Linux Rather than download Linux many users prefer to get a prepackaged version See WWWinwwrg for a list of companies that sell distributions Linux Distributions 5 Linux itself is free GPL GNU General Public License But is packa ed provided with installation and management tools and made availa le for a small fee by various vendors These packages are known as distributions Some common distributions are Red Hat redhatcom Fedora fedoraprojectorg Debian debianorg look at different ways to download amp install Ubuntu ubuntucom look at different ways to download amp install SuSE Mandrake Slackware TurboLinux Differences Locations of files configuration binaries etc GUI Security efficiency etc Included tools installation support UNIX Philosophy Make each program do w thing well These programs are sometimes called tools Expect the output of every program to be the input to another yet unknown program Simple tools can be connected to accomplish a complex task The concept of piping commands together is important here EX ls l wc Do not hesitate to build new tools The UNIX tool library keeps growing Layers in the UNIX System Users Standard Utility Programs shell editors compilers etc Library Interface System Interface calls Standard Library open close read write etc l User Mode UNIX Operating System process management memory management the file system IO etc l Kernel Mode Hardware cpu memory disks terminals etc UNIX Structure The kernel is the core of the UNIX system controlling the system hardware and performing various lowlevel functions The other parts of the UNIX system as well as user programs call on the kernel to perform services for them UNIX Structure The shell program is the command interpreter for the UNIX system The shell accepts user commands and is responsible for seeing that they are carried out There are various shells bash csh ksh tcsh sh We will learn the basics of shell navigation use and simple programming UNIX Structure Hundreds of utility programs or tools are supplied with the UNIX system These utilities or commands support a variety of tasks such as copying files editing text performing calculations and developing software We will learn about some of the basic tools commands UNIX Structure User programs or applications can be developed using UNIX utilities or purchased from software vendors These applications occupy the same logical position within the UNIX system as that of UNIX utilities v 0perating Systems Concepts 5 Objectives i Recognize and explain the difference between system and application software Identify and describe the functions and purposes of an operating system List and describe a variety of actual examples of contemporary operating systems and the devices on which they run Recognize and explain the meaning of various terms related to operating systems Questions i Software What is software vs firmware vs hardware What is application software What is system software Explain the difference between an operating system and application software Operating Systems Name some operating systems you know about andor have personally used Name some of the features what they do or what they let you do of an operating system Describe the purpose of an operating system 5 Brief Definition An operating system is 1 a computer program softwarefirmware that 2 manages and controls the computer system and 3 allows users to interact with the system User Interaction with 5 Operating Systems Operating System Terms A process or taskis an instance of a program in execution A thread is an individually executable part of a process Sometimes known as a lightweight process Operating System Terms An operating system is multitasking if it is capable of executing several tasks simultaneously An operating system is mutiuserif it is capable of supporting several users simultaneously NOTE By quotsimultaneousy we mean either truy simultaneousy because of multiple CPUs or apparent y simultaneousy because of timesharing on a single CPU In contrast if we use the term 39jbaraie we mean true simultaneous execution of tasks because of multiple CPUs Operating System Terms Some possible combinations include Singleuser singletasking systems EX Your Palm PDA Singleuser multitasking systems EX Your computer running the client version of Windows Ex Unix Linux running in singleuser mode Multiuser multitasking systems Ex A computer running the server version of Windows Ex Unix Linux running in multiuser mode Operating System Terms In an interactive process the user appears to have an interactive conversation with the operating system Ex Interactive payroll calculation Ex Interaction with ATM machine to withdraw cash Ex Interactive orderplacement on AmazonCom In a batch process the user submits a job for later execution by the operating system Ex Batch payroll calculation based on file containing employee IDs amp hours worked and exemptions etc file Ex Producing monthly bank statements based on all transactions rom the month including those interactive transactions such as ATM wit drawals Ex Endof day processing of all orders for that day and e mailing order confirmation statements Operating System Terms Operating Systems are divided into resdemand transient portions If the entire operating system were loaded into memory there would be no room for applications Transient Resident 10 Operating System Terms Resident Portion Must be in memory at all times Is loaded at bootup time Performs basic operations including starting and terminating programs and allocation of memory and files Known as the kerneor nucleus Operating System Terms Transient Portion Loaded into memory only when needed Various parts swapped in and out on demand This is typically handled by demandpaging Performs more complex tasks or tasks that are needed infrequently OS Services and Facilities There are 8 basic services and facilities that an operating system should provide 13 X OS Services and Facilities 1 The command processor application program interface and user interface Command Processor Command interpreter Shell bash csh ksh in Linux CommandCom in DOSWindows Usually provides for batch control statements programming Application Program Interface API Allows userwritten programs to have access to system resources applications User Interface Graphical User Interface GUI mouseoriented Command Line Interface CLI keyboardoriented 14 OS Services and Facilities 2 The InputOutput IO Control System The ability to communicate with existing and new IO devices In a PC the Basic IO System BIOS is in ROM ReadOnly Memory Extensions are provided by 10 device drivers Early programmers 19405 19505 had to communicate directly with hardware rather than going through the OS device drivers 15 OS Services and Facilities 3 Process Control Management Scheduling and Inter process Communication Determines the state of each process running ready to run waiting Dispatching or scheduling is the selection of which process to execute next based on some priority scheme Switching from one process to another in a fashion that all the details of the previously running process are preserved is called context shiting switching 16 Process Control Management Context Shifting Switching 39 rog ram process OS Services and Facilities 4 Memory management Deals with primary memory RAM Random Access Memory Keeps track of memory allocations to each process and prevents processes from writing to memory outSIde their allocated space Modern programs implement virtual storage virtual memory to allow large processes to execute In smaller amounts of real storage and to use any available memory addresses 0 What Is meant by quotVirtual storage Virtualstorage is typically implemented through quotdemand paging Inthis class we will use the terms virtual storagequot and Virtual memory interchangeably 18 Why is virtual memory needed Let s focus on the demandpaging aspect for a moment Examples for different types of machines For a 16 bit machine the OS can directly access 216 65536 bytes 65 Kilobytes For a 32 bit machine the OS can directly access 232 4294967296 bytes 4 Gigabytes 1 million times as much as a 16 bit machine For a 64 bit machine the OS can directly access 264 18 x 1018 bytes 18 Exabytes 1 billion times as much as a 32 bit machine This is 1 million billion times what we had with the original PC This is 1 quintillion How much memory do you have in yourcomputer How much memory can your computer actually address Not all machines can access the full theoretical amount that we have identified above If you want to run multiple programs operating system plus applications whose total memory requirements exceed the amount of memory the operating system can directly access you need demand paging so you can swap programs and data in and out of memory as needed See next slide for graphic representation 19 Virtual Storae N Portions of I program Prog 3 I i in memory portion 4 i Prog 2 2 P rogra 4 can be loaded an Prog 1 run at any available 0 Resident OS Disk address In RAM memory 20 OS Services and Facilities 5 The file management system Deals with secondary memory hard disk CDDVD tape Directory structure to facilitate the retrieval and storage of files Allocation and deallocation of file space Tools that copy and move files Provide information about files Method to easily move from one structure to another On multitasking systems There may be many processes requesting IO services from secondary storage at the same time Techniques are needed to optimize the completion of those tasks such as caching buffering etc Contemporary file mgt systems are networkaware and smart 21 OS Services and Facilities 6 Security and Protection Management Services to prevent unauthorized users access to the system File protection to keep unauthorized users from accessing files Contemporary security and protection mgt aspects of 055 are networkaware and smart 22 OS Services and Facilities 7 Network Management Communication Support and Communication Various levels allow for file transfer ftp scp copycp file sharing nfs samba remote logins ssh telnet rlogin rsh rdp remote process communication rpc etc 23 OS Services and Facilities 8 Support for System Administration Adding and deleting users Changing user privileges Monitoring security Providing secure backups Installing and upgrading software Upgrading the operating system Recovering lost data 24 IPv4 Network Add ress Resolution Netmask and Subnet Examples Dan Turk Colorado State University Netmasks Dan Turk Colorado State University Netmask Variations ClassA 255000 11111111000000000000000000000000 8 ClassB 25525500 11111111111111110000000000000000 16 ClassC 2552552550 1111111111111111111111110000000024 Split Octets 255255255128 1111111111111111111111111000000025 255255255192 1111111111111111111111111100000026 255255255224 1111111111111111111111111110000027 255255255240 1111111111111111111111111111000028 255255255248 1111111111111111111111111111100029 255255255252 1111111111111111111111111111110030 255255255254 1111111111111111111111111111111031 Of course you can have other variations by moving the split octet to the left 1 or 2 positions to split up a Class A or B parent ratherthan a Class C parent like what is illustrated on this slide Ex1111111111111111111100000000000020 Other Common Special 0000 00000000000000000000000000000000 O 255255255255 1111111111111111111111111111111132 Dan Turk Colorado State University Standard Netmasks What are the netmasks for each of the following standard networks Regular Classes Class A Class B Class C Internal NonRoutable Reserved 10000 10255255255 What size is this 1721600 17231255255 What size is each of these How many are there 19216800 192168255255 What size is each of these How many are there Dan Turk Colorado State University Netmask Example 1 S12982133751O 100000010101001010000101010010112 NM 25525525501O of source computer D 12982133501O 100000010101001010000101001100102 12982133751O 100000010101001010000101010010112 AND 2552552550 111111111111111111111111000000003 1298213301O 100000010101001010000101000000002 1298213350 10000001 0101001010000101 001 100102 AND 2552552550 111111111111111111111111000000002 1298213301O 100000010101001010000101000000002 l in SO itin Source and destination are on same local area network 12982133024 Therefore Use ARP to lookup get destination s MAC address Send directly to destination Don t use default gateway Dan Turk Colorado State University Netmask Example 2 S12982133751O 100000010101001010000101010010112 NM 25525525501O of source computer D 1298240751O 100000010101001000101000010010112 12982133751O 100000010101001010000101010010112 AND 2552552550 111111111111111111111111000000003 1298213301O 100000010101001010000101OOOOOOOO2 1298240751O 10000001 01010010001010000100101 12 AND 2552552550 111111111111111111111111000000002 129824001O 10000001 0101001000101000000000002 SO lLin W V 7 Source and destination are on different local area netwo 12982133024 and something else we don t know wh i til one is just that it s different ifi Therefore Use ARP to look up get default gateway s MAC address Send to default gateway Dan Turk Colorado State Univers Netmask Example 3 S1298240751O 100000010101001000101000010010112 NM 25525525201O of source computer D 1298242751O 100000010101001000101010010010112 1298240751O 100000010101001000101000010010112 AND 2552552520 111111111111111111111100000000003 129824001O 100000010101001000101000000000002 12982427510 100000010101001000101010010010112 AND 2552552520 111111111111111111111100000000002 129824001O 10000001010100100010100000000000 SO ill Source and destination are on same local area network 1298240022 Therefore Use ARP to lookup get destination s MAC address Send directly to destination Don t use default gateway NOTE We have decreased the size ofthe network 5 portion and increased the size of the host portion by using a different netmask Dan Turk Colorado Sta e UniverSIty Subnets Dan Turk Colorado State University Subnet Example 1 With a Class B parent network 129820016 for example The parent s Netmask 25525500 Q How many Class C subnets can there be What are the numbers of these subnets And how many hosts can be on each subnet Another way of asking this question is How many subnets with 256 hosts can we create Or another way of asking it is how many subnets can there be if our netmask is 2552552550 The answerto this of course depends on our parent network The 3rd octet specifies this Or another way of looking at it is that there are 8 bits available Within the given class B address space forthe network number portion and 8 bits available forthe host portion A Therefore there are 28 256 Class C subnets possible and each subnet can have 28 256 numbers 254 usable hosts 256 subnets 254 usable each of which may have 256 hosts 254 usable The numbers are 1298210 1298220 129822540 Q What about 1298200 A It s the network numberforthe whole Class B network Therefore it is reserved Q What about 129822550 gsl erggt number 255255 is the broadcast address forthe whole Class B network Therefore it is On the 1298220 subnet the allowed usable hosts are numbered from 1298221 through 129822254 There are 254 usable hosts on this subnet Q What about 1298220 and 129822255 A They are the subnet number and broadcast address respectively for the 1298220 subnet What if parent is 12982224020 its netmask is 2552552400 How many Class C subnets can there be now Answer other questions too Dan Turk Colorado State University Subnet Example 2 What if the Netmask forthe subnets is 255255255240 Given some Class C parent network say 12982133024 for example Q How many bits are used for the network portion and how many bits are used for the host portion for the child subnets Within the given address space 4 bits are used forthe network number and 4 bits are used for the host portion Q What is the largest size subnet that can exist other than a single subnet With 4 bits used forthe host portion there can be 24 16 hosts 14 usable on each subnet Q How many of these can exist With 4 bits used for the network portion within the class C address space there can be 24 16 subnets 14 usable Q What are the network numbers forthese subnets You ll have to pick a representative IP number prefix to work from Ifwe use 129821330 as the Class C parent network the valid subnets are 129821330 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240 But what about 1330 and 133240 230222oli lta nlg3r g ESLii339133Eesi533482 52lh 331353 ELI ES 523 quot be use 133255 is me Q What are the smallest 1st and largest last usable host numbers possible on one of these subnets On 1298213316 1298213317 and 1298213330 On 12982133224 12982133225 and 12982133238 What about on 255240 255255 Q What are the network number and broadcast addresses of one of these subnets On 1298213316 16 amp 31 On 12982133224 224 amp 239 Q What if the parent network is a Class B Dan Turk Colorado State University Sub net Example 3 Determine the most precise netmask that could be used in order to allow for a subnet of up to 5 machines Illustrate with an example In other words find the netmask show how you would determine the answer and then give as an example a valid parent network and child IP subnet number and the smallest and largest IP numbers that could be used for hosts on this subnet and the subnet39s broadcast address Q How many bits are needed forthe host portion of the desired subnet ln otherwords how many bits are required in order to allow for at least 5 usable addresses to be assigned on the network A 22 2 42 2 not enough 23 2 82 6 enough therefore we need 3 bits forthe host portion Q What netmask will this new subnet need to use A Since it will use 3 bits for host number then we need a total of 29 1 bits in the netmask This will be 255255255248 24810 111110002 or 29 Q What is a valid sample parent network and how many bits will it give us to manage A Since we need 3 bits for the host number on the desired subnet then we need at least 2 more bits for a total of 5 available to manage in the parent network Let s pick an easy example and use a Class Cquot size network where there will be 8 bits that we can manage Let s pick 129821330 with subnet mask 2552552550 for example Q How many bits will thus be left for the network number within the parent address space A Since we have 8 bits that we manage in the parent network and 3 bits are needed for host numbers on the new subnet then 83 5 bits are available for network number portion on this subnet Q How many subnets ofthis size could we create in our parent network A There are 5 bits available forthe network number within the parent address space so there are 252 322 30 usable networks of this size 6 usable addresses per network Q List the first 3 and last 2 usable subnetwork numbers that we could use A 129821330 not usable because the parent network s number would conflict with this subnet s network number 1298213381298213316 1298213324 12982133232 12982133240 12982133248 not usable because this subnet s broadcast address conflicts with the parent network s broadcast address Q Forthe 3rd usable subnet what is it s network number it s broadcast address and the 1St and last usable addresses A The 3rd usable subnet from the previous QA is 1298213324 this is the network number The 1St usable address is 1298213325 the last usable address is 1298 13330 and the broadcast address is 1298213331 Dan Turk Colorado State University ISP Example 1 With a Class B parent network 1298200 for example Netmask 25525500 Q How would I go about allocating multiple Class C size subnets to organizations as well as allocating numerous single IP addresses to individuals and not cause conflicts between these What if some people organizations wanted subnets that can have up to 10 hosts on them A We need to carefully think through where in our address space we want to allocate Class C size subnets where we want to allocate the 10 host subnets and where we want to allocate individual IP addresses lfwe don t think this through carefully we will either cause IP address conflicts or waste space So first off let s figure out the number of bits used for each ofthe two different size subnets Class C A Class C size network can handle up to 254 actual hosts and thus needs 8 bits for the host number portion thus leaving 8 bits within our Class B address space for the network number portion This means that if we totally divided our Class B address space up into subnets this size we could have up to 282 2562 254 subnets ofthis size each with up to 254 actual hosts on them gtgt Subnet NM 2552552550 10 hosts In orderto handle a network with 10 actual hosts we need 4 bits which will even allow us to have up to 14 actual hosts forthe hosts number portion thus leaving 12 bits within our Class B address space forthe network number portion This means that if we totally divided our Class B address space up into subnets this size we could have up to 2122 40962 4094 subnets ofthis size each with up to 14 actual hosts on them gtgt Subnet NM 255255255240 Next let s figure out what the allowed network numbers would be in each ofthese situations Class Cquot 129821012982201298230 129822520129822530129822540 1298200 and 129822550 are not usable because of conflicts they will have with the parent Class B network number and broadcast addresses 1 o hosts 12982016 12982032 12982048 129820240 1298210 12982116 129821192 129821208 129821224 129821240 1298220 12982255192 12982255208 12982255224 1298200 and 12982255240 are not usable because of conflicts they will have with the parent Class B network number and broadcast addresses Finally allocate ranges so they don t conflict and still allow us to sell subnets and single addresses as customers des1re Dan Turk Colorado State University Subnet Examples 46 What if Netmask 2552552520 1280 1920 Given some Class B parent network Q How many bits are used for the network portion and how many bits are used for the host portion Q What is the largest size subnet that can exist other than a single subnet Q How many of these can exist Q What are the network numbers forthese subnets You ll have to pick a representative IP number prefix to work from Q What are the largest and smallest usable host numbers possible on one of these subnets Q What are the network number and broadcast addresses of one of these subnets Work on these outside of class Dan Turk Colorado State University Subnet Example 8 What if Netmask 255255255248 Given some Class C parent network Q How many bits are used for the network portion and how many bits are used for the host portion Q What is the largest size subnet that can exist other than a single subnet Q How many of these can exist Q What are the network numbers forthese subnets You ll have to pick a representative IP number prefix to work from Q What are the largest and smallest usable host numbers possible on one of these subnets Q What are the network number and broadcast addresses of one of these subnets Q What if the parent network is a Class B Work on this outside of class Dan Turk Colorado State University OSI amp Networking Protocol i Architectures Broad Outline OSI vs TCPIP Model Preview The need for Networking Protocol Architectures Standards amp OSI TCPIP OSI amp Networking Architectures 2 TCPIP vs 051 Model Preview TCPIP 5 Application 4 Transport 3 Internet 2 Network Access 1 Physical 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data Link 1 Physical OSI amp Networking Architectures 3 Why Use a Protocol Architecture Data communications requires complex procedures Sender identifies data pathreceiver Systems negotiate preparedness Applications negotiate preparedness Translation of file formats For all tasks to occur high level of cooperation is required 051 amp Networking Architectures 4 Protocol A Protocol is Mutually acceptable conventions for specifying what how and when data is communicated A set of semantic and syntactic rules that describe how to transmit data especially across a networkquot Stallings 2005 p 99 100 565 Key elements syntax semantics timing Protocol Architecture The software structure that implements the communications function Typically layeredquot Stallings 2005 p 100 565 051 amp Networking Architectures 5 Modular Approach Break tasks into subtasks Each module handles specific subset of tasks Communication occurs between different modules on the same system red arrows on next slide And between physical modules on different systems red arrows on next slide between similar modules on different systems black arrows on next slide 051 amp Networking Architectures 6 OSI Process Illustrated Packet is illustrated illustrated by black Data Physical Physical Physical H J J a J V End System Intermediate Systems End System Source Routers typically Destination OSI amp Networking Architectures 7 Why StudyOSI Still the best model for conceptualizing and understanding protocol architectures Later networking classes and work assignments expect you to know and understand this model Key points Modular Hierarchical Boundaries between layersinterfaces OSI amp Networking Architectures 8 5 7From Umar 1993 p 574576 Service vs Protocol vs Standard A service represents the general functions performed by la er N for layer N1 Layer N can be viewed as a service providerquot or Layer N1 Layer N1 is a service userquot of layer N Layer N1 is one level above Layer N e 051 Data Link layer 2 is one layer above Physical layer 13 A protocol specifies the recise rules of information exchange between two eers andor layers A protocol specifies the message format and ru es to interpret and react to the messages Protoco s are the basis for interconnection and internetworking of different systems and are thus the visible aspect of 051 A standard is an agreed upon formal speci cation of the protocols andor the services 051 standards specify the 051 Reference Model the services to be provided by the different layers of the Model and the protocols for exchange of information between peers OSI amp Networking Architectures 9 OSI Terms cont Fm p End System vs Intermediate System An end system provides ALL services including the services above the Network 3 Layer Transport 4 Session 5 Presentation 6 and Application 7 Examples of end systems are computers on which applications reside End system is a synonym of host a term commonly used to refer to where applications reside An intermediate system only performs services related to the lowest three layers of the Reference Model eg routing and bit transmission c D F AltE gtH B G a V HJ End System Intermediate Systems End System OSI amp Networking Architectures 10 OSI Open Systems Interconnection Developed by ISO Contains seven layers I LNUObU39IGN Application Presentation Session Transport Network Data Link Physical OSI amp Networking Architectures 11 1 051 Physical Layer Physcal connection between 2 devices Responsible for transmission of bits Always implemented through hardware Encompasses mechanical electrical and functional interfaces wires pins signals voltages eg RS232 USB RJ45 CDMA GSM 900 1800850 OSI amp Networking Architectures 12 2 051 Data Link Layer Manage transmission of information across physical link S nchronization error control etc between directlyconnected evces Manages the physical layer Reception recognition amp transmission of tokens Directing traffic within a LAN on one side ofa router MAC media access control layer MACLAN addressing local area network LAN layer LANMAC addressing Examples CSMACD Ethernet Token Ring FDDI OSI amp Networking Architectures 13 3 051 Network Layer Unreliable Connectionless Routing Optimal Route Switching Crossmg Multiple Networks figuring out the next hop Examples IP Novell IPX X25 cf Umar 1993 p 5836 can be in any of layers 13 Call setup transfer clear disconnect Provides 2 circuit types Virtual similar to dialup line Permanent similar to leased line IP addressing OSI amp Networking Architectures 14 4 051 Transport Layer Relable Connect0n endtoena connection ordered errorfree data stream endtoend error recovery Packetizing break up amp reassemble Examples NetBEUI Microsoft NetBIOS Extended User Interface cf Renaud p 201 transport and network layers Not Routable not across networks not through routers TCP Transmission Control Protocol Routable Sockets Ports may fit here Novell SPX OSI amp Networking Architectures 15 5 OSI Session Layer EndtoEna communication between applications Full Duplex Control Buffering Set up connections Reestabish dropped connections Examples NetBIOS Microsoft Sockets Sun may fit here Fit better in transport layer Ports may fit here Fit better in transport layer 051 amp Networking Architectures 16 6 051 Presentation Layer Provides format and code conversion services Not the GUI look and feel Examples File conversion from ASCII to EBDIC to Unicode to Invoking character sequences to generate bold italics etc on a printer Little endian big endian the order bits are stored in memory 8bit 16bit character encoding Encryption decryption SSL OSI amp Networking Architectures 17 7 051 Application Layer The actual application Examples XWindow FI39P telnet ssh smtp DNS Distributed DBMS Online registration Online banking Amazoncom ordering etc Overview of variety of network addressing mechanisms Domain Names IP Addresses Ethernet Addresses Ports Domain Name Addressing OSI amp Networking Architectures 18 g 051 Process Illustrated Packet path is illustrated by red arrows Applilation 39 Packet Applj ation Packet headers Preseltation headers removed Preseltation Seslsion added on and info Seslsion way down inspected Tranlsport on wa up Trar39sport NetIIork 4 Network I 4 Network I 4 Network I Netllork Datel Link Data Link Data Link Data Link Datel Link Phytical gt I PhysicalV gt I PhysicalV gt I PhysicalV gt Phytical H J J a J V End System Intermediate Systems End System Source Routers typically Destination OSI amp Networking Architectures 19 OSI Process Illustrated Application A Application Presentation presentation Session A Session Transport Transport Network letwork W W Network Data Link ink Data Link Data 39 Data Link Physical Physical Physical Physical Physical H J J H V End System Intermediate Systems End System Source Routers typically Destination Conceptual path is illustrated by black arrows OSI amp Networking Architectures 20 051 in Action Outgoing File Transfer FTP application program issues command to transfer a file OR confirm order on Amazoncom Application layer passes it to Presentation which may reformat perform conversions encryptdecrypt passes to Session Session requests a connection passes to Transport Transport breaks file into chunks passes to Network Network selects the data s route the next hop one step closer to destination passes to Data Link Data Link adds errorchecking info handles directly connecteddevice flowcontrol passes to Physical Physical transmits data which includes information added by eachlayer OSI amp Networking Architectures 21 051 in Action Incoming File Transfer i Physical receives bits passes to Data Link Data Link checks for errors handles directly connected device flowcontrol passes to Network Network verifies routing Intermediate system passes down to Data Link and on down as outgoing packet End system passes up to Transport Repeat layers 123 through all intermediate systems until reaching the destination end system Transport reassembles data correct sequence all arrived errorchecking passes to Session Session determines if transfer IS complete may end seSSIon passes to Presentation Presentation may reformat perform conversions encryptdecrypt pass to Application layer Application presents results to user eg updates FTP program display OR stores order data in Amazoncom s database 051 amp Networking Architectures 22 TCPIP vs 051 Model Preview TCPIP 5 Application 4 Transport 3 Internet 2 Network Access 1 Physical 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data Link 1 Physical OSI amp Networking Architectures 23 TCPIP Transmission Control ProtocolInternet I 5 Appllcatlon prOtOCO 4 HosttoHost Developed by DARPA transport early 19805 3 Internet No official protocol I 2 Network Access standard 39 1 PhySIcal Can identify five layers OSI amp Networking Architectures 24 1 TCPIP Physical Layer Physical interface between a DTE data terminal equi ment eg computer or terminal an a transmission medium Specifies Characteristics of medium Nature of signals Data rate Similar to mechanical aspects of RS232 Implemented in workstations and routers end and intermediate systems OSI amp Networking Architectures 25 2 TCPIP Network Access Layer Exchange of data between end system and network between directlyconnecteddevicesquot Address of host and destination Prioritization of transmission Software at this layer depends on network eg packetswitching vs Ethernet Segregation means that no other software needs to be concerned about local net specifics Implemented in workstations and routers end and intermediate systems MAC media access control layer MACLAN addressing local area networkquot layer LANMAC addressinCI OSI amp Networking Architectures 26 g 3 TCPIP Internet Layer IP Internet Protocol An internet is an interconnection of two or more networks Internet layer handles tasks similar to network access layer but between networks rather than between nodes on a network Uses IP for addressing Implemented in workstations and routers end and intermediate systems Routin layer 051 amp Networking Architectures 27 51PM Header 20octets octet byte 8bit block 4bit version number 32bit source and destination IP addresses 16bit checksum for IP header 8bit protocol number other items Max size dataheader 65535 bytes Typical 1480 bytes OSI amp Networking Architectures 28 IPv6 Header 40octets octet byte 8bit block 4bit version number 128bit source and destination addresses required to support number of systems connecting to internet and private networks See httpenwikipediaorCIwikiIPv6 for more info valid as of 2011 Jan 31 See httpwwwfadsorcIrfcsrfc2460html for IPv6 definition 2011 Jan31 OSI amp Networking Architectures 29 4 TCPIP Transport Layer TCP Transmission Control Protocol Also called hosttohost endtoend layer Reliable exchange of data between applications Uses TCP protocols for transmission Implemented 0nyin workstations end systems 051 amp Networking Architectures 3O g TCP Header 20 octets octet byte 8bit block 16bit source and destination ports identify applications using connection 32bit sequence number for reassembling in proper order and endtoend flow control 32bit acknowledgment number next expected seq for flow control 16bit frame check sequence for TCP Header data integrity CRC other flags and optional parts Data 1500 bytes 051 amp Networking Architectures 31 s 5 TCPIP Application Layer Logic needed to support variety of applications Separate module supports each type of application eg file transfer Implemented 0nyin workstations end systems OSI amp Networking Architectures 32 CPIP Operation 5T Suppose process at port 1 at host A wishes to send message to process at port 2 host B Process at A hands message to TCP with instructions to send it to host B port 2 TCP hands message to IP to send to host B TCP may have to break message into multiple pieces hence sequence numbers in header IP hands message to network access layer eg Ethernet to send to router X first hop to B Network access layer adds info and sends packet across physical link OSI amp Networking Architectures 33 TCPIP Operation con t Router X receives packet Network access header contains MACLAN addressing info IP header contains subnetwork info address priority etc Removes network access packet header examines destination address information in IP header and directs datagram out across appropriate subnetwork to B by adding new network access header When finally received at B each layer removes its header and passes remainder to upper layer until original data delivered to destination process OSI amp Networking Architectures 34 Some TCPIP Protocols for which applications exist Simple mail transfer protocol SMTP accepts message from application uses TCP to send it to an SMTP module on another host where passed to local e mail package File transfer protocol FI39P FFP sets up TCP connections for messages Separate TCP connection for data transfer telnet applications running at both ends to mimic terminal TCP used to transfer terminal traffic ssh Secure shell encrypted telnet OSI amp Networking Architectures 35 BGP I I FTP I IHTTPI ISMTPI ITELNETI ISNMPI TCP UDP I ICMPI I IGMPI I OSPF I I RSVP I IP BGlquot FTP HTTP 9 ICMIP IGMP 1P MIME lll ll ll ll Border Gateway Protocol File I39ranst er Protocol Hypertext quottransfer Prntocol Internet Control Message Protocol Internet Group Management Protocol Internet Protocol MultiPurpose Internet Mail Extension OSPF RSVP SMTP SN M P TCP U DP ll ll Open Shortest Path First Resource ReSerVation Protocol Simple Mail Transfer Protocol Simple Network Management Protocol Transmission Control Protocol User Datagram Protocol OSI amp Networking Architectures 36 g TCPIP v 051 Most production software uses TCPIP rather than 051 Why has 081 lost the war TCPIP became defacto standard because of use in industry What is the value of 081 051 is a conceptual model that more finely divides up the networking space OSI amp Networking Architectures 37 TCPIP vs 051 Model Preview TCPIP 5 Application 4 Transport 3 Internet 2 Network Access 1 Physical 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data Link 1 Physical OSI amp Networking Architectures 38 Intro amp Overview v Of Distributed Systems ClientServer An architecture Client requests services of server Server provides services and replies back to client lookup storage computation Client performs part of overall application GUI data entry display Components Hardware Computers Ex MainframeTerminal vs ServersPCs MainframePCs etc Software Operating system services Ex ftp web serverclient Application programs Ex Webbased frontendclient database backendserver Network Components Hardware Computers Routers Cabling Transmission Routing Software User Protocols Architecture Transmission Routing Networks and subnetworks Security General CSU CoB Network Devices General COB omlmxaumimnem Network amp Devices Wm Q g wa Base nenl Switch RWW 1quot F 0039 Switch wa 2quot Floor Switch COB Ma39 Switch gtSF and Internal 0U er C 6 ATS male Patch Panel Main Sil Qwest Nationwide Network Willi Fiber MIRher timer Consimt an quot1quot 012151335 Qantas I L Global Network Example Intro amp Overview of Distributed Systems 7 g a See mapnet for interactive map of worldwide Internet backbones httpvaNwcaidaorCItoolsvisualizationm a net Interesting to view but the graphical representation is now a bit outdated 2002 last update See VisuaIRoute for visual traceroute httDvisuaroutevisuawarecom Connections Full Physical Connectivity Full physical interconnectivity NN12 connections for N computers 2 computers gt 1 connection H 3 computers gt 3 connections A E 4 computers gt 6 connections 7 computers gt 21 connections 10 computers gt 45 connections 100 computers gt 4950 connections 1000 computers gt 499500 connections Half a million connections for only 1000 computers How would we ever connect the millions of computers around the world Connections Logical Connectivity Networked connectivity N K R connections N N computers connected into subnets via hubsswitches etc K K interconnections for K subnets R number of redundant backup interconnections EX Ex 90 computers in 9 LANs of 10 computers each with 3 subnets interconnecting 3 LANs each and 1 toplevel net interconnecting the 3 subnets NN12 9 4005 connections if fully interconnected N90 K12 R 9 approximately 100 connections if subnetworked 10 Connections Various Network Perspectives LAN MAN WAN A local area network LAN is a computer network covering a small geographic area like a home of ce or group of buildings eg a school The de ning characteristics of LANs in contrast to Wide Area Networks WANs include their much higher data transfer rates smaller geographic range and usually a lack of a need for leased telecommunication lines Wide Area Network WAN is a computer network that covers a broad area ie any network whose communications links cross metropolitan regional or national boundaries m Or less formally a network that uses routers and public communications m M Contrast with personal area networks PANs local area networks LANs campus area networks CANs or metropolitan area networks MANs which are usually limited to a room building campus or speci c metropolitan area eg a city respectively The largest and most wellknown example of a WAN is the Internet Quotes are from Wikipedia 2008 Feb 4 Intranet Extranet and the Internet Internet demographics 2011 Jan 31 htt enwiki ediaor wiki List of countries b number of internet users httpwwwinternetworldstatscomstatshtm httpwwwinternetworldstatscomstat525htm Facebook 11 Connections Various Network Perspectives I Intranet An intranet is a private computer network that uses Internet protocols and network connectivity to securely share part of an organization39s information or operations with its employees Sometimes the term refers only to the most visible service the internal website The same concepts and technologies of the Internet such as clients and servers running on the Internet protocol suite are used to build an intranet HTTP and other Internet protocols are commonly used as well such as Q There is often an attempt to use Internet technologies to provide new interfaces with corporate legacy data and information systems Brie y an intranet can be understood as a private version of an Internet or as a version of the Internet confined to an organization The term rst appeared in print on April 19 1995 in Digital News amp Revewin an article authored by technical editor Stephen Lawton L1 I Extra net Quotes are from Wikipedia 2008 Feb 4 An extranet is a private network that uses Internet protocols network connectivity and possibly the public telecommunication system to securely share part of an organization39s information or operations with suppliers vendors partners customers or other businesses An extranet can be viewed as part of a company39s Intranet that is extended to users outside the company eg normally over the Internet It has also been described as a state of mind in which the Internet is perceived as a way to do business with a preapproved set of other companies businesstobusiness BZB in isolation from all other Internet users In contrast businesstoconsumer BZC involves known servers of one or more companies communicating with previously unknown consumer users 12 Connections Various Network Perspectives the Internet The Internet is a worldwide publicly accessible series of interconnected comguter networks that transmit daj by packet switching using the standard Internet Protocol IP It is a network of networks that consists of millions of smaller domestic academic business and government networks which together carry various information and services such as electronic mail online chat m transfer and the interlinked web pages and other resources of the World Wide Web WWW The International Network or more commonly known as the Internet and the World Wide Web are not synonymous The Internet is a collection of interconnected comguter networks linked by cogger wires beroptic cables wireless connections etc In contrast the Web is a collection of interconnected documents and other resources linked by hyperlinks and URLs The World Wide Web is one of the services accessible via the Internet along with various others including email m sharing online gaming and others Quotes are from Wikipedia 2008 Feb 4 13 Types of Communication Voice telephone Image still Video motion Data all other info transfer Question Are these becoming artificial distinctions Question In what ways are these distinctions important 14 Issues in Transmission of i Information Across Networks I MEdia Wire groundlines wireless Copper fiber Satellite radio Modes Analog Digital Techniques Encoding Compression Multiplexing Efficiency Security 15 Types of Data Signals Analog W ConUnuous Voice telephone 3000 Hz CD 20000 Hz 20 Hz 20 KHz Digital Discrete Though binary IS very common DIGITAL DOES NOT IMPLY BINARY Voice 8000 Hz x 8 bits sample 64000 bps 64 Kbps 0064 Mbps CD 44100 Hz x16 bits sample x 2 channels 141 Mbps 16 Measuring Data Transmission I Units 1000X 210x 1024X K Kilo thousand 103 1000 N 210 1024 M Mega million 106 1000000 220 1048576 G Giga billion 109 1000000000 230 1073741824 Quantity Bytebit Bb KBKb KiBKib MBMb MiBMib GBGb GiBGib TBfl39b Ti BTib Bandwidth Hz KHz MHz GHz Bpsb s KBpsKbps KinsKibps MBpsMbps MinsMibps GBps Gbps GinsGibps 17 Conclusions and What Next So we see that there are many issues in networking Hardware Software Efficiency Transmission Reliability Security When we examine the 031 model it will provide us with a way to help get a handle on this complexity and to help organize the issues systematically 18 i Internet Addressing Types of Addresses Question What types of networking Internet addresses do you use are you familiar with Name as many as you can Internet Addressing 2 Outline Example networks getting around Types of Addresses Hardware Logical Example address resolution etc Ports Internet Addressing 3 College of Business Network College of Business WEE sm39ifa ii i i m Local Area Nerork g ggsgig 82 133 I 1 25 a 3335 mascarameans NIC 1 IP gum FF AS m 1 003 NIC 1 Emma address Daiaun gaieway M 129 32133 0 NW Mg Faun 1 Mei i 429 52133 46 82 133 0 EIJ45 67 39 AB CD39EF 1O Gbps Dedicated to CSU Main Route In Engineenr g P129 82 4044 EU55 7B QNBC39DE FD Fibeir iv Lab amp Classimm Suture I29 82 400 NIC Fi29 82 401 Nelworked Plinier Elh12 3456 78 SA BC 29 8240 4 5 7 89 ABCDEFOI Default galeway rm 12992 400 NW Nal nal Business Lab 5 Ciassmom Emiigg ggg g g 2 Owes LeveiS Lambda niernel2 Rail 2932 40 129mm 29 8142 12982 43x 2552552520 IF 29 82 4 quotkm 52 45 Eth8939lBCDEFJOX 23 Elh9ABCDEFU391234 Internet Addressing 4 9 Sample LANWAN El iwmmqg gwmmg 13D WEE 1 El Netwurk Wurkstatmn Wurkstatmn Wurkstatmn Wurkstatmn Wurkstamn Wurkstamn Wurkstatmn 188 168 A 22 Wurkstatmn 188 168 6 112 18816828 18816848 Wurkstatmn Wurkstatmn Netwurk Netwurk 188168156 1nterraceE1 18816821 mterrace E8 18816861 Warfare 58 1nterraces1 18816852 1nterraces1 18816851 Warfare E8 1881681 1 Warfare 58 172 82 1 1 F ETSSES r1 Wan RouherA CDHHEEUDH Router 5 Internet Addressing 5 Networking Resources on the Web SubnetOnIineCom s subnetting guides and calculators httDwwwsubnetonlinecom A simple subnetting calculator httpwwwsubnetonlinecomsubcalcsubnet8html Another even simpler subnetting calculator htt wwwsubnetonlinecom subcalc subnet7htm Another more complex subnetting calculator htt wwwsubnetonlinecom subcalc subnet9html Yet another subnetting calculator httpzwwwsubnet calculatorcomcidrphp A Java subnetting calculator that lists subnet info htt wwwsubnetonlinecom subcalc subnet2htm Another Java subnetting calculator with slider control httpwwwsubnetonlinecomlsubcalcsubnet4htm RFC 3021 31 networks httpzwwwfagsorgrfcszrfc3021html Local remote packet destination calculator httpwwwsubnetonlinecomsubcalcsubnet1html IP to Bin calculator httpwwwsubnetonlinecomznetcalcziptodechtm Base conversions httpwwwsubnetonlinecomtoolsdechexbinhtml Binary IP calculations httpwwwsubnetoninecomsubnetsteplhtml CIDR Classless InterDomain Routing Overview htt enwiki ediaor wiki Classless InterDomain Routin htt enwiki ediaor wiki CIDR notation NAT Network Address Translation Overview httpcomputerhowstuffworkscomnathtm All sites valid as of 2010 Sep 12 Internet Addressing 6 Types of Addresses for computer networking Computer Domain Hardware MAC El39hemetAddr48 bit Logical In colostateedu lamarco 05 a eedu wwwusatoda com wwwstatecous hurricane 19270175125 wwwbizcolostateedu www2 12982133248 panthergsuedu 1319616 dantbizcolostateedu 1298240106 whitehousegov 19813724143 Check out wwwICANNorg Internet Corporation for Assigned Names and Numbers and IANA htt wwwianaor fa s abusefa htm Check out wwwinternicnet Try out the Registry Whois and search for the colostateedu domain then scroll down and see what it tells you Look in the Accredited Registrar Directory Application Service I P I C 39 80 H39I39I39P Internet Addressing 7 Hardware Addresses 5 MAC Media Access Control Ethernet IEEE 8023 very common 48bit address 12 hexadecimal digits grouped in 6 pairs EX 0003476FFFFF OR OOO3476FFFFF 1612 248 approx 280000000000000 unique addresses 280 trillion 280 million million Unique worldwide supposedly Used to identify packet destinations on final local network actually a layer 2 addressmg Used to fdirect packets through level 2 switches and hubs mm a LAN local subnet We use the word direct here rather than route since we typically use the word route to mean level 3 routing through routers and across multiple networks Internet Addressing8 Internet IP Addressing The current version IPv4 defines a 32 bit address This means there are approximately 232 or 4294967296 addresses available 43 billion This seems like a lot but we are quickly exhausting the available addresses Part of the problem is that the allocation of addresses wasn t handled very efficiently classbased and giving large blocks to single organizations New standard IPv6 based on 128 bits is being developed 34 x 1038 addresses 3400ooooooooooooooooooooooooooooooooooo Seg htt enwiki ediaor wiki IPv6 for more info valid as of 2011 Fe 7 NAT network address translation helps deal with some of these ISSUES Also httpcomputerhowstuffworkscomnathtm 2011 Feb 7 Internet Addressing 9 Domain Name Service DNS DNS converts between domain naming and IP numbering conventions Name server primary secondary nslookup looks up nameserver resolves domain names to IP addresses try amarcoostateedu wwwusibmcom googlecom I WhOiS on some machines tells full domain name wwwinternicnet info on domain names registrars Other network utilities ipconfig all Tells network config info about the local machine I netstat a netstat tupan Tells network connection status port etc info about the local machine traceroute tracert on PCs Traces the route packets will take from local machine to specified destination Indicates how long and number of hops Ping n w Checks to see if there is working network connection between the local machine and a specified destination ARP a s Maps between MAC and IP addresses on a local network Intern Addressmg 39 10 Classbased Internet IP Addressing Key 1 Global perspective from outside the organization This perspective identifies a standard Network Number portion and a Host Number portion depending on the IP address 32 bit addresses divided into two parts o a prefix that is routable and that identifies the network o a suffix that identifies the individual computer However see httpZenwikipediaorglwikiZClassless Inter Domain Routing for CIDR cassess contrast I NetworkH um bar I HostH urn her i Ellquot l HetwwkF re x I HostH uh her i Internet Addressing 11 IP Address Issues IP was standardized in 1981 Each computer is uniquely identified While there is global management of the prefix numbers the suffix numbers are left to local administration The question here is How many of the 32 bits to assign as network addresses if you assign too many then you connect fewer computers ie suffix space is short If you assign too few then you connect too many computer ie suffix space is long Internet Addressing 12 IP AddressinCI Classes 39 Class bin 31 F a 31 l l HustHumlanr II 211553 hit I 2 15 1E 31 lml l IMethrkflumhaH H03Hlumh3 h Class2 tit I 3 23 24 31 11n H ulst l Network Hunter II Nlmherll39 Internet Addressing 13 i Same thing different view hi I z 4 21 31 Human 9 prefix suffix Elass Mal prefix gum cums l11a prefix mm H Elass hl11ul multimuddrm H mm hl1l11 rmwmarlutmm I Internet Addressing 14 I hit DottedDecimal Notation III 51 I IIJIIIilIIIIIIIli IEIEIEI1III1IJ i i IIIIIIIIIIEIIJH 1451 H343 145 Address ICisss I D ettedDeeimsi Hotelier Fisn ges Mia prefixes 1Issesssstrrsugh 12Emsexstsss 0 and 127 are reserved 10xyz are nonroutable 1230ssstseexthrsly h191255sse sense 2 600 17231255255 are nonroutable B i 15 pre xa 152IIIIIIsstirsugh 225255255ssse 192168Xy are nonroutable Internet Addressing 15 I i24 pre xes IP Addressing Format The address itself contains the key to identifying where the network bits end and the suffix bits begin This in turn defines how many addresses are assigned to each class address Based on the previous two slides if you extract the first four bits of an address you can identify the class of an address Internet Addressing 16 g Computing the Class of an Address First Four Table llndex Class of its Of Address in decimal Address 0990 o A I Each Class A has an 2 8bit address prefix am 3 A network portion quot100 4 A Each Class B has a 0101 5 A 0110 e A 16bIt address pre x 0111 139 A network portion 1000 8 B 1001 g B Each Class C has a 1010 10 B 24bit address prefix 1011 11 B 1m 12 0 network portion 1101 13 c 1110 14 D 1111 15 E Internet Addressing 17 Division of the Address Space Address Bits In Maximum Number Bits In Maximum Number Di Glass 7 Prefix of Memories Suffix Hit51 Per Network A 1 23 2394 1577 7215 3 id 16384 16 65535 G 21 21197152 E 256 Actually 8 16 amp 24 bits are in the prefix but 1St 123 bits are specified for each class and thus only 71421 bits are usable for network numbers We ll always focus on the total number of bits in the network portion 8 16 or 24 Class A get 2147483648 of all IP addresses Class B get 1073741824 of all IP addresses Class C get 536870912 of all IP addresses Total 3758096384 total Class A C IP addresses NOTE There are actually fewertotal useabe addresses than this since some addresses are special and are reserved Internet Addressing 18 What does it take to get a Class A address i A Class A would require more than 65536 hosts Class B can handle up to 65536 hosts Even so two or three contiguous Class 85 would handle almost every company on the planet You get a Class C unless you can definitively demonstrate that it is inadequate for your needs Class C can handle up to 256 hosts Even then you will probably be assigned a group of Class Cs Internet Addressing 19 Examples of DottedDecimal Notation 32bit Binary Number 10000001 00110100 00000110 00000000 39HEIIDDDEIEI ndnnmm 00110000 DUD D H 00001010 00000010 00000000 00100101 10000000 00001010 00000010 00000011 10000000 10000000 11111111 100001100 Equivalent Dctlud Decimal 129 52 IE0 192 5 15 3 m E l 13quot 125 10 2 12312325513 Range will be 0000 to 255255255255 Half of all IP addresses are assigned to the Class A addresses Internet Addressing 20 Special Reserved IP Add resses cf pp Loopback 127xyz 127001 typical This computer 0000 Undirected Limited local net broadcast a binary 1 s 255255255255 Directed specified net broadcast netbinaryls x255255255 or xy255255 or xyz255 or xyz15 etc possible sometimes Network netbinary05 x000 xy00 xyz0 or xyz16 etc possible sometimes Nonroutable 10xyz Can t be use to route on the 192168xy Internet From local net through ISP Can only be 721600 used in local network 17231255255 including local routers Internet Addressing 21 Netmasks Key 2 Internal perspective from Within the organization from within a given local area network LAN We will call the or anization s network that we are working within the parent network and we will call t e new network we are designin creating the child network or the subnet Almost totally forget about classbase de initions except possibly for the parent net space we are working within Keys 3 amp 4 A netmask is used to determine the portion of the IP address that identi es a network network portion and thus which portion is used to identij machines host portion on a given subnetwork If the host number portion is totally binary 0s then the IP is a network if it is totally binary 1s then the IP is a broadcast address Examples 25500010 111111110000000000000000000000002 8 1st 8 bits network portion final 24 host portion 255255255010 111111111111111111111111000000002 24 1st 24 bits network final 8 host 2552550010 111111111111111100000000000000002 16 1st 16 bits network final 16 host 255255252010 111111111111111111111100000000002 22 1st 22 bits network final 10 host Q How many hosts can be on this network Internet Addressing 22 Physical Address Resolution The Final Destination Problem The The Data Link Layer only understands 48bit Ethernet Addresses or physical addresses Higher layers understand only 32bit IP address not physical addresses How is the IP address mapped to the physical address Every machine actually every network interface not just computers has a unique MAC media access control address Internet Addressing 23 Possible Solutions Could keep a table showing everyone s IP and MAC addresses o consider how difficult this would be to maintain if thousands of machines are involved Another option is to ask who owns IP address XYZA o Broadcast this on XYZ0 the current sub net using FFFFFFFFFFFF this is an Ethernet broadcast every machine will check its IP address o XYZA will respond with its MAC address actually all machines on the local net will likely respond o Sending machine builds the appropriate Ethernet frame o ARP Address Resolution Protocol broadcast does this Internet Addressing 24 ARP Address Resolution Protocol Almost every machine on the Internet runs ARP When MAC addresses are learned via ARP they are then stored temporarily in a local table for future use Lost on reboot unless stored statically Does not work across routers only local net It is an Ethernet level LAN broadcast Cgt ARP a Cgt ARP S Cgt ARP d Internet Addressing 25 g Why ARP i Simple to use Network administrator doesn t do anything except assign IP addresses Can cutdown on ARP broadcasts by having each machine identify itself when it boots up o this puts the appropriate ARP entry in everyone s cache 0 handle stale caches by timing out entries Internet Addressing 26 Routing Getting between local networks Problem MAC addresses work only on local nets We need to go between local nets Internet Addressing 27 Possible Solutions Have the router respond when another subnet is referenced eg cs from cis this is called a proxy arp proxy arp keeps a table of networks it will respond for Have source host identify that destination is on a different network and just send the traffic to the default router gateway more general than a proxy arp solution Internet Addressing 28 Then What Router gets packet inspects the IP address then checks its table Might broadcast an ARP message to get the physical address for the next router forwards packet Repeat until packet arrives at router connected to final LAN Final router gets traffic inspects IP address if necessary it broadcasts an ARP message asking destination computer to identify its MAC address Message is sent in to LAN and destination machine picks up and processes packet Internet Addressing 29 What about traversing multiple routers Problem Somehow the router needs to determine where to send a packet when its destination subnet is not directly attached Solution Keep tables of known networks netmasks next hopsquot and default destination This is a routing table Various protocols keep router tables uptodate RIP Routing Information Protocol OSPF Open Shortest Path First IGRP Interior Gateway Routing Protocol BGP Border Gateway Protocol Internet Addressing 3O College of Business Network College of Business WEE sm39ifa ii i i m Local Area Nerork g ggsgig 82 133 I 1 25 a 3335 mascarameans NIC 1 IP gum FF AS m 1 003 NIC 1 Emma address Daiaun gaieway M 129 32133 0 NW Mg Faun 1 Mei i 429 52133 46 82 133 0 EIJ45 67 39 AB CD39EF 1O Gbps Dedicated to CSU Main Route In Engineenr g P129 82 4044 EU55 7B QNBC39DE FD Fibeir iv Lab amp Classimm Suture I29 82 400 NIC Fi29 82 401 Nelworked Plinier Elh12 3456 78 SA BC 29 8240 4 5 7 89 ABCDEFOI Default galeway rm 12992 400 NW Nal nal Business Lab 5 Ciassmom Emiigg ggg g g 2 Owes LeveiS Lambda niernel2 Rail 2932 40 129mm 29 8142 12982 43x 2552552520 IF 29 82 4 quotkm 52 45 Eth8939lBCDEFJOX 23 Elh9ABCDEFU391234 Internet Addressing 31 9 Sample LANWAN El iwmmqg gwmmg 13D WEE 1 El Netwurk Wurkstatmn Wurkstatmn Wurkstatmn Wurkstatmn Wurkstamn Wurkstamn Wurkstatmn 188 168 A 22 Wurkstatmn 188 168 6 112 18816828 18816848 Wurkstatmn Wurkstatmn Netwurk Netwurk 188168156 1nterraceE1 18816821 mterrace E8 18816861 Warfare 58 1nterraces1 18816852 1nterraces1 18816851 Warfare E8 1881681 1 Warfare 58 172 82 1 1 F ETSSES r1 Wan RouherA CDHHEEUDH Router 5 Internet Addressing 32 Examples Netmask ARP Hubs Switches amp Routing See examples slides for details Internet Addressin 33 5 Ports i TCPIP allows multiple applications to use its services at one time Each service is identified by a protocol port number In the UNIX world these ports for IP are defined in etcprotocols Internet Addressing 34 i Some wellknown ports ort 11 20 21 22 23 25 37 80 443 109 110 161 3389 There are many more These are just afew examples Process Name USERS FTP FTP SSH Telnet SMTP Time HTTP HTTPS POP2 POP3 SNMP RDP Descrigtion Active Users FTP Data FTP SSH Telnet SMTP Current Time HTTP HTTPS Post Office Prot 2 POP3 SNMP Remote Desktop Internet Addressing 35 g TCP Ports e In the Unix world stored in the etcservices file So ssh is service 22 How this works IP in word 3 of header protocol field has the value 6 for TCP deencapsulates TCP header word 1 destination port has the value of 22 for ssh Internet Addressing 36 iCh 1 Introduction Outline What is computer networking Brief History of Computing Business Resources and IS Components Centralization vs Distribution What is Computer Networking What is computer networking What are some examples of networks we seeuse in our daily personal andor work Hves What are the components of a computer network So a couple questions Briefly in summary What is the point of networking Why network A Brief History of Com 1940519705 Mainframe Mini Super 1970519805 PC 0 0 19805 Networked PC 39i t 1 19905 Workstation l i 39 l 19905 Workstation and Server PC5 WWW A 397 ll 20005 Wireless PDA5 and integrated mobile devices that connect to the WWW and to servers tablet PCs 7 20105 Just started we ll see quot Brigg It s interesting that we ve come pretty much full circle in some aspects of computing CentralizationDecentralization Centralized I Ex Mainframe Terminal 5 I EX Server MS Terminal Services 39 MainFrame Distributed Ex WWW Decentralized quot Ex Standalone PC s Textbook doesn t use this term Textbook includes this idea as one vartion of distributed Business Resources Traditional have been consciously identified as business resources for many years 39 v V Money Materials People Information Age quot have been COnSCiouSIY added as business resources only since the information age Information Data r Question is Are computer networks an additional unique resource They certainly are a resource gig 7 1 Computerized Business IS Components Traditional Hardware Software People Procedures I Data Question Are computer networks an additional unique component They certainly are a means of communication iVirtual Environments host Graphical View Vi rtualizer H Lpossibylthe Virtualizer host Option 1 Run Linux or Windows or another OS native on the host Option 2 Run some applications native but run other 05 s and apps under them virtually IBM zseries host This is what we ll be doing in our VMware Server Linux and Windows assignments There are 34 host machines with about 20 gues VMs on each host Option 3 there are other options too IBM mainframe host with various native and virtual machines in different LPARs logical partitions 5 LPARs are used in this example Virtual Environments 2 Networking Class vLAN VMware Server portion Na meserver 1298210378 amp 79 VLAN 19216840023 Access only from within CSU and only via ports Gateway 192391683940391 22 ssh 80 http 443 https 3389 rdp 8222 VMware 8333 VMware secure 902 for VMware I Is 39th39l WIC l l l 1921684011 1921684012 1921684013 19216840 19216840 Ubuntu host Ubuntu host Ubuntu host 14 15 Ubuntu host Ubuntu host VMware server VMware server VMware server VMware VMware server server LinUbuntu VMs 19216840100 WinServerVM LinUbuntu VM VMs VMs 19216841100 Win7VM IOtherVMs VMs Virtual an ronments 3 Networking Class vLAN VMware ESXi portion Nameserver 1298210378 amp 79 VLAN 19216840023 Access only from within CSU and only via ports Gateway 192391683940391 22 ssh 80 http 443 https 3389 rdp 8222 VMware 8333 VMware secure 902 for VMware I I I I Swrtch I I Should be completed by Friday then we can discuss the design Virtual anironments 4 Overview of VMware Server Design The machines physically exist in RWE 152 we access them through a vLAN virtual local area network from a CSUauthenticated machine over the Internet Intel 64bit hosts Intel i7 920 Intel Quadcore and AMD64 824 Gb RAM each max on each machine 300 Gb boot disk each 3006b or 1Tb RAIDO Vmware Server is our virtualizer on each host Ubuntu Linux 1004 is the host OS on each host VMware allows us to create virtual Linux and Windows Instances or guests We will have about 20 virtual Linux instances and about 35 virtual Windows instances Each instance has an IP number 1921684023 and 4123 Ubuntu 1004 Windows 2008 Server R2 and Windows 7 are the guest OS s Virtual Environments 5 Overview of VMware Server Design Should be completed by Friday then we can discuss the design Virtual Environments CIS350 Operating Systems amp Networks Department of Computer Information Systems College of Business Administration Colorado State University Fort Collins Colorado Spring 2011 Jan 19 7 May 12 200 7 250 pm MWF Rockwell West 209 Dan Turk ami 1250 pm WF by appointment 152 4910467 E Mail to me T urk Daniel Dr in RamCT Mail E Mail T do not use for class correspondence Via Remote Posting as responses to assignments using RamCT Exam May 12 200400pm This Syllabus Provides a General Plan for the Course Deviations May Be Necessary CIS350 Syllabus 7 Spring 2011 Course Description and Prerequisites prerequisites will be enforced Multiuser and network operating systems basic networking concepts including security transmission performance and topologies Prerequisite CIS210 Colorado State University General Catalog 20102011 General Objectives This course covers a variety of Operating Systems amp Networking topics These topics may include but are not limited to 1 Concepts andor Handson arwr39r39wqorm 996 Overview Number systems Network Addressing Virtual Machines UNIX Linux amp Windows ISO OSI Model Wired vs wireless technologies Protocols Topologies Security Encryption Errordetection Signals amp Transmission Issues amp Ethics 2 Handson and or Concepts a CEOH1999quot UNIX Linux amp Windows Basic installation administration and security scripting software RAID web servers Wikis Blogs Cloud services Samba LVM etc Hardware Wireless Problem solving Security permissions con guration Routing DNS CIS350 Syllabus 7 Spring 2011 The successful student should be able to recognize identify explain describe compare and contrast analyze and apply knowledge in each topic addressed throughout the semester Some general objectives follow Upon completion of this course the successful student will be able to In general 1 Describe explain name list identify and recognize the concepts components and uses of operating systems networking 2 Demonstrate through handson activities the ability to setup and troubleshoot hardware and software for a computer network in Linux and Windows 3 Compare and contrast various approaches to networking describe or identify tradeoffs to each approach and explain or recognize ways to choose which type of network to implement in a given situation Some specifrcs not comprehensive 1 Explain Operating Systems processes process management 2 Understand and explain number systems and how binary and decimal are used in networking 3 Work effectively with basic MS Windows and Linux administrative and security tasks including working from the Linux command line 4 Manage network and web functions on Linux and Windows 5 Manipulate Linux les with lll understanding of the underlying directory structure and security 6 Program simple Linux shell scripts 7 Explain memory and le systems and how they apply to various operating systems 8 Explain the OSI and TCPIP networking models and their roles in networking and the Internet 9 Understand amp explain how network addressing and routing is performed in computer networks 10 Understand and explain how to measure network performance 11 Understand the role of wireless transmission in network implementations and some of the technologies currently in use 2 Describe compare and contrast and explain the uses of various types of encryption technologies including symmetric eg DES AES and asymmetric e g RSA techniques 13 Program simple network applications if covered CIS350 Syllabus 7 Spring 2011 Textbooks and other references and resources Primary RequiredRecommended Resources Dean Tamara 2010 5th ed Network Guide to Networks Thomson Course Technology ISBN 9781423902454 Required main textbook Blum Richard 2008 Linux Command Line and Shell Scripting Wiley ISBN 9780470251287 Required Linux textbook Negus Christopher 2010 Linux 2010 Edition Wiley ISBN 9780470 485057 Required Linux textbook Von Hagen William 2010 3rd ed Ubuntu Linux Featuring Ubuntu 1004 LTS Wiley ISBN 9700470604502 Optional Linux textbook Other Recommended Resources Newham Cameron amp Rosenblatt Bill 1998 2nd ed Learning the bash Shell O Reilly ISBN 1565923472 Previous recommended Linux textbook Now out of print Garrels Machtelt 2008 Bash Guide for Beginners httpwwwtldporgLDPBash BeginnersGuideBashBeginners Guidepdf Visited 2010 Jan 19 Recommended Linux Bash shell tutorial reference Olenewa Jorge amp Ciampa Mark 2007 2nd ed Wireless Guide to Wireless Communications Thomson Course Technology Kirch Olaf amp Dawson Terry 2000 2nd ed Linux NetworkAdministrators Guide O Reilly ISBN 1565924002 Tomsho Greg Tittel Ed amp Johnson David 2003 3rd ed Guide to Networking Essentials Thomson Course Technology Welsh Matt Dalheimer Matthias Kalle amp Kaufman Lar 1999 3rd ed RunningLinux O Reilly ISBN 156592469X Books on MS Windows Networking CIS350 Syllabus 7 Spring 2011 Grading Categories and Breakdown Categories Tests amp 50 All tests amp quizzes Quizzes Individual 50 All assignments and Group HW Total 100 Breakdown Note that grading is used 95 A 90 A 87 B 83 B 80 B 77 C 73 C 60 D below F NOTE 1 This breakdown indicates lower limits of the letter grade you will receive if you earn at least the score given in the chart NOTE 2 See group project grading handouts to be provided as the semester progresses for details of how grades are assigned for group work based on a combination of individual and group performance and teacher and peer assessment Teacher and Student Commitments to this Class In order for all of our experiences in this class to be the best they can be it is imperative that both I as the teacher and you as the student make commitments to fully invest ourselves in this class From that perspective I as the teacher of this class commit to do the best I can to be prepared for class each day to have materials that you need for class and assignments ready for you on time and to grade and return homework assignments and tests in atimely manner I commit to helping provide an open and safe classroom learnin environment where everyone is treated with respect and no questions are considered quotstupidquot I commit to providing the help that I can within the limitations of reasonable amounts of of ce hours and email interactions to help you with questions outside of class I commit to being fair in my assessment of your work and assigning of grades though can assure you that this does not meanI will simply be quoteasyquot Grades are always assigned based on how well you perform on and complete the assignments and tests required of you in this class 5 CIS350 Syllabus 7 Spring 2011 At the same time you the student commit to attending all class periods except in the case of truly unavoidable emergencies and to come to class prepared and ready to participate through discussion and interaction This involves reading material ahead of time asking relevant questions and responding appropriately to questions during class and doing your homework in a quality and timely way and having it turned in before or by the stated deadline You the student commit to helping ensure that the classroom learning environment is open and safe treating all students and the teacher with respect and considering that no questions are quotstupidquot You commit to coming and asking for help as soon as you have questions not waiting days or even weeks before coming to get help You commit to providing appropriate feedback when asked or on your own so that the class can be improved because of your insights Finally you commit to accepting personal responsibility for your grades based on how well you perform on and complete the assignments and tests required of you in this class Notes about Grading Grades are given based on how well you complete the assignments not on the amount of time or effort you put in and not on the amount that you think you have learned Unfortunately there is great variation in how much time it takes to complete any given assignment Just because it takes one person 20 minutes to complete and another person 1 hour complete does not mean they earn different grades it also does not necessarily imply that the assignment that took 20 minutes will receive a better or worse grade than the one that took an hour to complete Likewise the only way Ihave to assess what you have learned is in how well you perform on assignments and tests and how well you participate in group and inclass activities In order to assess these things there will be specific tasks required of you and it is these tasks for which you will earn specific grades The questions that are used to assign you a grade on any given task include but are not limited to 1 How well were the instructions for the assignment followed 2 Was the assignment turned in on time 3 What level of quality did the final submission possess 4 How much of the assignment was done correctly 5 Were ideas and principles discussed in class applied and followed in carrying out the assignment CIS350 Syllabus 7 Spring 2011 Approach to Course Lectures This course will be taught organized around the assignments that will be given for the semester What this means is that the days certain topics are covered may vary a little or a lot from how they are listed in the course schedule since we will drive our discussions and lectures based on how well the class interacts participates and grasps the concepts that are discussed and which are needed for doing each assignment This also means that it is unlikely that we will go directly through all the lecture slides We will however cover all or most of the material in class it just won39t likely be in the exact sequence that it is listed in the slides and textbooks The reason this will be done is because Ithink that it will make the content more relevant and it will tie the content directly to the assignments you will be assigned I will expect signi cant class participation and feedback regarding this approach Scheduled Tests amp Final Exam There will be four tests including the nal exam They will cover the lecture book handout homework and project material even if it was not covered in class and may be any combination of truefalse multiplechoice matching programming short answer and essay styles and handson These tests will be spaced approximately evenly throughout the semester about every 3 4 weeks with the nal test coming during test week at the end of the semester Exact test dates will be set at least one week before the test is to be given All tests will be equallyweighted including the nal exam Each test basically covers the new material covered since the previous test none of the tests are comprehensive including the final exam Tests are typically closedbook closednote closedneighbor No mp3 players PDAs cellphones headphones or other electronic devices are allowed in class during tests On most tests calculators will not be allowed you will be alerted to the times when they are allowed Leave all these at home or at the very least keep them put away in your backpack or briefcase during the test Make sure they are totally out of site and inaccessible so there is no question in my mind as to whether you are using them or not you should not be On test days you will typically only need a pencil and an eraser for lling out ScanTron forms and responding to shortanswer test questions In general calculators are not allowed If a calculator is allowed you will be told beforehand and it must be a simple calculator and not one on a PDA cell phone computer etc and not a programmable one Make sure you take care of all quotbathroom breaksquot before coming to the test If you have a cold bring tissue with you to the test No one will be allowed to leave and return during the test period CIS350 Syllabus 7 Spring 2011 Quizzes There will probably be numerous unannounced quizzes These will usually occur at the very beginning of class but could occur any time There are no makeup quizzes The lowest quiz score will be dropped If you miss a quiz for excused or unexcused reasons then that quiz becomes the one that will be dropped Of course after missing one quiz all subsequent missed quizzes will be counted as zeros in your testquiz score Individual Homework A number of individual homework assignments will be given throughout the semester The details of these assignments and their due dates will be provided as the course progresses These assignments are to be done individually see Individual Work and Professional Standards of Scholarship sections below All assignments are due at the beginning of class on the due date for the assignment most of them will be required to be emailed or submitted online in another manner and received by me before the beginning of class time All work turned in for a grade should be done to the same level of quality as would be expected in a professionalwork environment This means that all submissions should be neatly typed use proper grammar and punctuation have correct spelling follow standard writing style guidelines give credit when material is quoted used andor referenced etc Staple multipage submissions do not turn them in unattached Points may be deducted if multiple pages are not stapled together See more detailed explanations below under Individual Work and Professional Standards of Scholarship Sometimes use of various media slides computer presentation live video and toolstechniques Powerpoint Visio Rational Rose etc are recommended Group Homework A number of group homework assignments will be given throughout the semester The details of these assignments and their due dates will be provided as the course progresses These assignments are to be done in teams See Individual Work and Professional Standards of Scholarship sections below A single submission for each assignment will be required for each team All assignments are due at the beginning of class on the due date for the assignment most of them will be required to be emailed or submitted online in another manner and received by me before the beginning of class time Linux amp Windows Operating Systems Networking Projects You will be doing several major projects this semester with Linux and Windows You will be working on your own or possibly in groups at the teacher s discretion of approximately 2 team members throughout the semester on these projects installing and configuring mininetworks here at CSU documenting and testing the process and make recommendations regarding tools you use In general you will be installing Linux Ubuntu Windows 2008 Server and Windows 7 and creating servers and clients on your quotmininetworksquot Topics you may work with include various aspects of Active Directory Windows security settings and processes Windows amp Linux installation of 8 CIS350 Syllabus 7 Spring 2011 application software Windows amp Linux including blogging and wiki servers sharing resources between Windows amp Linux creating webservers Windows amp Linux and possibly tools for creating and pushing out client images Windows You will also be working with VMWare and making virtual servers and clients The details of this project will be provided as the semester progresses Late HW Missed Tests Etc Late work is generally not accepted All submissions are due before the beginning of class on the date speci ed unless otherwise explicitly noted in class via email and or on the class RamCT site Frequently the assignment will be reviewed during the rst few minutes of class on the day it is due No work will be accepted after it is reviewed in class There will be NO MAKEUP TESTS given unless you have a universityapproved excuse and contact me BEFORE the test in question is given Tests and homework will not be excused simply for vacations etc Schedule your vacations for after the semester is completely finished including the final exam Individual Work All work submitted for a grade must be done only by those who will be receiving a grade for the submission To do otherwise is considered plagiarism is not acceptable and you can be dismissed from the University because of it This includes individual homework group homework if such is assigned tests and quizzes 7 any work submitted for a grade Work submitted as your own but which was done all or in part by others will not receive full credit 7 in fact it is likely to receive no credit This is known as plagiarism and is dealt with very seriously If you draw on previous work done by others be sure to give appropriate credit when this is the casel When you are asked to work alone make sure you do that In short since you are each unique individuals I expect to be able to easily tell from the work you submit that you worked independently collaborative work tends to jump out at me because it looks suspiciously similar to something I ve already seen Make sure you work suf ciently independently so that I can easily tell that you have done your own work A penalty will be assigned to those who submit collaborative work when it was assigned to be done individually The minimum penalty is usually a ZERO on the assignment but University Policy allows for more serious penalties when warranted The University requires that I report to the University level any time a grade is reduced because of academic dishonesty or related issues See University policy on Academic Integrity for further details There are times when you are asked to quotshow your work on assignments This means that you will not get full credit if you only give the nal answer It means that you are required to show the process and logic that you followed in order to obtain the answer This may require you to list formulas and the steps used in applying the formulas including intermediate values Be sure to show your work if you hope to get full credit For details see section entitled Professional Standards of Scholarship 9 CIS350 Syllabus 7 Spring 2011 Professional Standards of Scholarship Professional standards of scholarship require that any time an individual relies on another s work proper credit must be given This means that any time one directly uses textual material that it must be placed within quotes and referenced properly other non textual material must be shown with proper credit given citing the original source of the work When material is not used in exact form paraphrased major ideas relied on or referred to etc it should still be given credit as well although it is not put within quotes Always give credit to ideas or materials that are not yours Ifin doubt give credit Violations of these standards are highly disapproved of and appropriate academic action will be taken depending on the situation University policy requires that I report to the University level any situations where a reduced grade is assigned because of plagiarism or other quotacademic misconductquot reasons Be professional give credit where it is due turn in work that is your own and you will be fine IF YOU ARE UNCERTAIN ABOUT HOW TO DEAL WITH THESE ISSUES PLEASE TALK WITH ME I AM HERE TO HELP YOU LEARN AND TO HELP YOU WHEN YOU ARE UNCERTAIN ABOUT WHAT TO D0 DO NOT HESITATE TO ASK QUESTIONS Besides expecting professional standards of scholarship generally accepted US standards for written work will applied to documents turned in for this course This means that grammar punctuation spelling and citation of references should follow standard guidelines APA American Psychological Association or another common standard is acceptable for work submitted for this course Be consistent be neat be professional You are receiving a degree from an American university which you and the University want to be wellrespected Thus you will be held to relevant American academic standards See University policy on Academic Integrity Misconduct for further details 2 This includes software source code as well Always give credit when you rely on someone else s ideas examples algorithms source code etc 10 CIS350 Syllabus 7 Spring 2011 Participation While inclass participation is not directly taken into account when determining course grades it is expected during class lectures as well as via email during group project meetings and during group project work This course may involve new ideas and almost certainly requires learning new skills and behaviors with respect to your software installation con guration and troubleshooting habits Thus participation in class is anticipated to be bene cial and full involvement is expected Teacher Student Communications E Mail RamCT etc The best way to contact me is via RamCT email Log into this course in RamCT and send email to the instructor and I will probably respond within 24 hours of receiving your note Mostly likely within just a few minutes or hours I check mail many times a day almost every day of the week and expect you will probably do likewise I will expect to be able to send email to each of you and to get prompt replies I will use RamCT email to send mail to you as well so make sure you check it regularly even if you use some other account as well for the rest of your email RamCT will be used to post information homework assignments notices schedule changes etc basically everything for this course You will want to visit this site frequently If you have questions regarding any of this please ask right away You are responsible for all announcements and any schedule changes made in class even if you were not at class Find out from your friendsclassmates if there were announcements when you were not present I will use RamCT to post notices schedule changes etc that are not able to made in class Messages will be sent to your RamCT email account see above I will expect to receive all email from you via your RamCT email account not my CoB account Anything sent to my CoB email account will have to be resent to my RamCT email account in order to receive a response Almost all assignments and handouts are distributed in electronic form nonpaper through RamCT pages that I continually update throughout the semester You will want to visit them frequently i VNC Virtual Network Computing Outline Functions of VNC Setting up VNC server Connecting with VNC viewer SSH tunnels port forwarding VNC Functions of VNC Provides a graphical desktop sharing system similar to Microsoft s Remote Desktop Usually used for remote access to another computer Open source Various implementations Tight VNC Real VNC httpenwikipediaorCIwikiVirtual Network Com puting 2011 Feb 28 VNC 3 Setting up VNC server On server Install vnc4server once per server machine sudo aptget install ubuntudesktop sudo aptget install vnc4server Configure vncserver once per user account Run vncserver Enter password Edit vncxstartup Comment out all but 1St executable line Add gnomesession amp as additional line at end Or other desktop manager if gnome is not desired Write vncserver startup script etcstaItVNCserver killall Xvnc One line for each desired session geometry Stop and restart your vncserver Frequently runs as Xvnc Run your script and it will stop and restart Xvnc On client C Install vncviewer or run it if it s already installed Connecting with VNC viewer On client 1 Configure amp connect with ssh putty tunnels portforwarding Select local ports destination host and destination port for each tunnel Ex L 64003 localhost5903 Use port numbers 5901 5905 for teacher s sessions Use port numbers 5911 and 5912 for student sessions Save session configuration for later use 2 Connect via vncviewer on local machine to desired local port Ex localhost64003 enter VNC password Use local port that corresponds to your tunnel Teacher s will be 64001 64005 Student s will be 64011 64012 VNC SSH tunnels port forwarding VNC ssh tunnel local port ssh tunnel destination amp remote port Client SSH Connection port 22 5 HT nnl hr n n m lil ssh packet has vnc packet inside it vncviewer vnc server destination and listening port connecting port Local port 64003 forwarded to remote VNC port 5903 via ssh port forwarding Number Systems v 3 Number systems can 4 sometimes be confusing v Try these on for size They may not be what 39 you think they are 43 and 252 40 equivalent 39 101o1oo or 224 cl 100 but 64 cl f 1 and 1 1 Why not 1 and 1 2 g 101 and O 0 Why not 101 and O 101 Sometimes the binary system just doesn t seem to make sense but there are always exactly10 choices only O and 1 2 53313 Objectives i Recognize and be able to demonstrate how different types of information are represented as numbers binary decimal etc Be able to count in base 2 Recognize be able to give and be able to apply bit positions powers and place values in base 2 and base 10 Identify and be able to list and describe the largest and smallest signed and unsigned numbers and the number of combinations that can be represented given a certain number of bits a certain size block of memory Recognize and be able to list the names and abbreviations used for various quantities of memory bit byte kilobyte megabyte etc Convert between base 2 and base 10 both directions Recognize and explain the difference between various character codes such as ASCII EBCDIC and Unicode Motivation i What netmask should I use if I need to have a network with up to 20 machines on it How many machines can be on a network with a netmask of 255255255240 How many machines can be on a network if we have 6 bits allocated to it How much memory can a 32bit 64bit machine access How many Class B networks can exist using IPv4 lElpw many bits are needed in order to have a network with 1100 machines on If I am an ISP who has a Class B 16bits network address space how should I carve this address space up in order to most effectively sell these addresses to customers What is the largest unsigned integer that can be stored in 5 bits Or how many machines can I put on my LAN if my network administrator says I have 5 bits to work with How many bits are used for network portion and for host portion in a 25 network using IPv4 Are the two addresses 129824055 and 129824372 on the same or different networks And how do we determine this Counting systems bases amp symbols There are many ways to count Humans developed a number system based on 10 the decimal number system Base 10 requires 10 symbols O123456789 Base 10 Decimal Our number system base 10 is also a positional system Each number position has a special meaning Ex 1 s 10 s 100 s columns place values for decimal base 10 Ex 1 5 2 5 4 5 8 5 columns place values for binary base 2 In each position we put one symbol or one digt The number 235 is different from the number 523 235 has the symbol 5 in the ls column the symbol 3 in the 105 column and the symbol 2 in the 1005 column 523 has the symbol 3 in the ls column the symbol 2 in the 105 column and the symbol 5 in the 1005 column Number Systems Explained What does the number 23510 actually mean The 10 subscript tells us this is a base10 number Column POWer yew In base 10 each osition needs to be 1005 105 1 102 101 100 multiplied by a CH ferent power of ten 2 5 The rightmost position is always raised to x the zero power and we call It the Oth 2 1 0 position or the ls ones column smce Position 1 NOTE The rightmost column in all bases is always the 1s column since it is always the base raised to the 0 power and since anything raised to the 0 power is 1 7 Base10 Power Summary I 100 1 u 101 10 u 102 100 1010 103 1000 101010 104 10000 10101010 105 100000 1010101010 106 1000000 101010101010 Place Values What is the placevalue for position 6 in Base 10 Position 1 Position 3 Base 10 An Example 23510 2X102 3X101 5X100 2X100 3X10 5X1 200 30 5 Base 10 Another Example 984610 9X103 8X102 4X101 6X100 9X1000 8X100 4X10 6X1 9000800406 Base 2 Binary Most digital computer systems work internally with binary data base 2 rather than base 10 Base 2 Symbols amp Powers Base 10 numbers require 10 symbols O123456789 Base 2 binam requires 2 symbols The standard is 01 In Base 10 each position is multiplied by powers of 10 In Base 2 each position is multiplied by powers of 2 Base2 Power Summary 20 1 21 2 29 512 22 4 22 210 1024 23 8 222 211 2048 24 16 22272 212 4096 25 32 213 8192 26 64 214 16384 27 128 215 32768 I 28 256 u 216 65536 Place Values What is the placevalue for position 6 in Base 2 Position 1 Position 3 15 Base 2 An Example 1001011002 the 2 subscript tells us this is a base 2 number 1X28 OX27 OX26 1X25 OX24 1X23 1X22 OX21 OX2O 1x256 OX128 0X64 1X32 0X16 1X8 1X4 OX2 OX1 256003208400 3OO10 300 in base 10 We have just converted from binary to decimal Column s Place Value Binary Number Conversions Bit Pattern Bit Numeriq Power Position Value of 2 0000 0001 0 ones1 2 0000 0010 1 hNos2 21 0000 0100 2 4 22 0000 1000 3 8 23 0001 0000 4 16 24 0010 0000 5 32 25 0100 0000 6 64 26 1000 0000 7 123 27 Note that the rightmost bit position is designated as position 0 not position 1 17 Bits Bytes and other Units of Memory Measurement Since the number of bits in computer storage is so large computer memory is usually measured in bytes rat er than bits 1 bit 1 binary digit 1 binary symbol 1 small storage location in memory EX0 EX1 1 byte 8 bits 8 small storage locations 1 larger storage location EX01101101 EX11111111 EX00000000 Memory Measurement Terms Kilobyte KB Equals 210 or 1024 bytes KiB kibibyte see httbenwikibediaorqwikiKibibvte visited 2010 Aug 31 Approximately 1000 bytes 103 KB Megabyte MB Equals 220 or 1048576 bytes MiB mebibyte Approximately 1 million bytes 1000 Kilobytes 106 MB 19 Memory Measurement Terms Gigabyte GB Equals 230 or 1073741824 bytes Approximately 1 billion bytes 1000 Megabytes 109 Terabyte TB Equals 240 or 1099511627776 bytes Approximately 1 trillion bytes 1000 Gigabytes 1012 20 Memory Measurement Terms Petabyte Equals 250 or 1125899906842624 bytes Approximately 1 quadrillion bytes 1000 Terabytes 1015 Exabyte Equals 260 bytes or 1152921504606846976 bytes 1000 Petabytes 1018 21 Memory Measurement Term Summary ame Power 2 Decimal Value Bytes bit b 1 symbol 18 Byte B 8 bits 20 100 1 Kilobyte KB 210 103 1024 Megabyte MB 220 106 1048576 Gigabyte GB 230 109 1073741824 Terabyte TB 240 1012 1099511 527775 Petabyte PB 250 1015 1125899906842624 Exabyte EB 260 1018 1152921 504606846976 Each higher measurement is approximately 1000 times the size of the one before Actually each is exactly 210 1024 times 22 Octal amp Hexadecimal Number Systems Computers typically store binary data on or off 1 or 0 true or false A main storage listing is an enormous string of 039s and 139s not too convenient 23 Octal amp Hexadecimal Number Systems Consequently many representations of storage are done in either Octal Base 8 Hexadecimal Base 16 24 v Base8 Power Summary 80 1 81 8 82 64 83 512 84 4096 85 32768 25 Base16 Power Summary I 160 1 I 161 u 162 256 u 163 4096 I 164 65536 Base 10 Conversions Converting from base 10 to base 2 1 Find largest base 2 power less than or equal to the base 10 number being converted write this binary number down put a 1 in the correct position 2 Subtract the base 2 number from the base 10 number and repeat steps 1 and 2 until you get to zero when you subtract 3 Add all the base 2 values up This is the base 2 number equivalent to the original base 10 number See example on next slide 27 Base 10 Conversions Example convert 3710 to base 2 3710 3210 1000002 largest base 2 power lt 3710 3710 3210 510 410 1002 largest base 2 power lt 510 510 410 110 110 12 largest base 2 power lt 110 110 110 010 Stop 1000002 1002 12 1001012 3210 410 1103710 1 1 O O 1 O 1 325 16s 85 4s 25 is 1001012 28 5 Base 10 Conversions To convert base ten to base n Repeatedly divide the decimal integer by n saving the remainders until a quotient of O is obtained In each subsequent division divide the quotient found in the previous division The equivalent base n number is formed from the remainders the first top remainder is the rightmost digit the last bottom remainder is the leftmost digit 1 See example on next slide 29 Base 10 Conversions Example convert 3710 to base 2 37 2 18 remainder 1 100101 18 2 9 remainder O 9 2 4 remainder 1 42 2 remainder O 22 1 remainder O 1 2 O remainder 1 3710 1001012 30 Base 10 Conversions Example convert 826910 to base 16 8269 16 516 remainder 13 D16 516 16 32 remainder 4 32 16 2 remainder O 2 16 O remainder 2 826910 204016 31 Computer Number Storage Integers An integer is a whole number with no fractional decimal portion EX 32 75 10273 127 0 Not 325 190 12312 00 Stored as the binary representation of the decimal number 8 16 32 or 64 bits are used depending on integer size Most computer languages let you specify the number of bits to use 32 This is one of the most important slides of this section Computer Number Storage For Integers The number of combinations different possible unique values that can be represented in 0 bits is 27 The largest nonnegative unsigned value that can be stored in n bits is 201 The smallest is always 0 39tIJ39he range of signed values that can be stored in n its is 2 391 23973911 using 2 s complement storage 33 Computer Number Storage I Integer EX 8 10ftwo possible values in each I n 8 bltS position 0 or 1 I 28 256 8 bits allow us to represent 256 different values combinations 281 2561 255 The unsigned values that can be stored range from 0 to 255 I 27 128 271 1281 127 The signed values that can be stored range from 128 to 127 Integer EX 163155 I n 216 65536 16 bits allow us to represent 65536 different values combinations 2161 655361 65535 The unsigned values that can be stored range from 0 to 65535 215 32768 2151 32768 1 32767 The signed values that can be stored range from 32768 to 32767 34 Computer Number Storage Range of nonnegative integers that can be stored using unsigned integer storage 1 byte 8 bits 0 through 255 2 bytes 16 bits O to 65535 4 bytes 32 bits O to 4294967295 35 Computer Number Storage Represent the unsigned nonnegative integer 6110 as a 16 bit integer 6110 1111012 Using 16 bits 00000000001111012 Written in hex 003D16 We ve already illustrated this in the preceding slides 36 Storage of other data types We now briefly compare and contrast the storage of other data types with how we have described unsigned integers Signed integers Floating point Characters We do not look at the specifics of how images still and moving and sound are stored at this point 37 Negative Number Storage Signed Magnitude Allocates 1 bit as a sign bit A sign bit of zero represents a positive number a sign bit of one represents a negative number 61 would look like using 16 bits 1000000000111101 38 Negative Number Storage Signed Magnitude Several drawbacks One is that ZERO has two representations 1000000000000000 0 0000000000000000 0 This greatly complicates the hardware needed to perform calculations 2 s Complement To represent a negative number in binary invert the digits for the non negative value and then add 1 Ex with 4 bits 7 gt 71 0111 1 1000 1 1001 Ex with 4 bits 15 gt 151 1111 1 0000 1 0001 gt NOT VALID this is a valid 4bit nonnegative number 110 gt this is why the most negative number we can store is 2 39 15 is 2 1 8 is 2 391 Ex with 4 bits 8 gt 81 1000 1 0111 1 1000 gt max ne 2 391 Ex with 4 bits 7 gt 0111 gt max nonneg 2n3911 See additional examples handout as well 39 Negative Number Storage The magnitude of signed numbers stored is essentially half that of unsigned numbers 32768 to 32767 for a 16 bit signed number O to 65535 for a 16 bit unsigned number 40 Negative Number Storage Range of signed integers that can be stored 1 byte 8 bits 128 to 127 2 bytes 16 bits 32768 to 32767 4 bytes 32 bits 2147483648 to 2147483647 41 Floating Point Very large or very small numbers are represented using scientific notation Example 145654 X 1056 145654E56 145654 is called the mantissa or fractional part 56 is called the exponent 56 indicates that the decimal place will be moved to the right 56 positions A negative exponent would move the decimal point to the left 42 Floating Point Computers use floating point notation to store scientific numbers Floating point numbers are usually either 32 64 or 80 bits long One possible allocation of bits for a 32 bit floating point number is Sign 1 bit Exponent 8 bits Mantissa 23 bits 43 Precision Problems 6 digits of precision would mean that 10000000 and 10000045 would be treated as the same number 100000E7 and 100000E7 not 10000045E7 which has 8 digits of precision Not appropriate for business applications because rounding loss of detail occurs 44 Floating Point For a 32bit number Range 34E38 to 34E38 Precision is only 6 decimal places For a 64bit number Range 17E308 to 17E308 Precision is 16 decimal places For an 80bit number Range 34E4932 to 34E4932 Precision is 18 decimal places 45 Character Representations Characters are stored as fixed length bit patterns Common character set standards EBCDIC Extended Binary Coded Decimal Interchange Code An 8 bit code used on IBM mainframes ASCII American Standard Code for Information Interchange 7 bit code 46 Character Representations Extended ASCII Added 1 bit to standard ASCII 8 bit code First 128 characters are standard ASCII 128 additional characters are for graphics and line draw Introduced by IBM in the original PC Became the de facto standard for PC s Also known as the PC character set 47 International Character Sets 256 characters is insufficient for many languages Some languages contain as many as 10000 symbols Many nonstandard solutions in specific products address this problem 48 g The Unicode Standard Developed in 1991 by a consortium including Microsoft Apple HP Novell Symantec Became an ISO standard in 1993 16 bit code 2 bytes 49 Summary When we look at memory we have to 1 Decide how big a block to look at 1 bit 8 bits 16 bits etc 2 Decide how to interpret the data Unsigned integer signed integer floating point character etc 3 Decide how to display the data Binary octal hexadecimal decimal character graphic sound Video etc The same block of memo could be interpreted andor displayed in multip e ways We have to be careful to interpret display it in the appropriate and most understandable useful way
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'