1. LINUX NETWORKING TOPIC 6.0

2. Internet Protocol (IP) in UDP/IP and TCP/IP IP is the network layer packet delivery service (host-to-host). translation between different data-link protocols.

3. IP DATAGRAMS IP provides connectionless, unreliable delivery of IP datagrams. Connectionless: each datagram is independent of all others. Unreliable: there is no guarantee that datagrams are delivered correctly or at all.

4. IP ADDRESSES IP is a network layer - it must be capable of providing communication between hosts on different kinds of networks (different data-link implementations). The address must include information about what network the receiving host is on. This makes routing feasible.

5. IP ADDRESSES IP addresses are logical addresses (not physical) 32 bits. Includes a network ID and a host ID. Every host must have a unique IP address. IP addresses are assigned by a central authority (Internet Corporation for Assigned Names and Numbers -- ICANN)

6. SERVICES PROVIDED BY IP Connectionless Delivery (each datagram is treated individually). Unreliable (delivery is not guaranteed). Fragmentation / Reassembly (based on hardware MTU). Routing. Error detection.

7. IP DATAGRAM FRAGMENTATION Each fragment (packet) has the same structure as the IP datagram. IP specifies that datagram reassembly is done only at the destination (not on a hop-by-hop basis). If any of the fragments are lost - the entire datagram is discarded (and an ICMP message is sent to the sender).

8. UDP (USER DATAGRAM PROTOCOL) UDP is a transport-layer protocol communication between processes UDP uses IP to deliver datagrams to the right host.

9. PORTS UDP/IP uses an abstract destination point called a protocol port. Ports are identified by a positive integer. Operating systems provide some mechanism that processes use to specify a port.

10. PORTS Host AHost B Process

11. UDP Features Datagram Delivery Connectionless Unreliable Half-duplex Source PortDestination Port LengthChecksum Data UDP Datagram Format

12. TCP (Transmission Control Protocol) TCP is an alternative transport layer protocol supported by TCP/IP. TCP provides: Byte-Stream Connection-oriented Reliable Full-duplex

13. TCP vs. UDP Q: Which protocol is better ? A: It depends on the application. TCP provides a connection-oriented, reliable byte stream service (lots of overhead). UDP offers minimal datagram delivery service (as little overhead as possible).

14. IPX / SPX Internetwork Packet Exchange/Sequenced Packet Exchange networks using the Novell NetWare OS. IPX is a network layer protocol SPX is a transport layer protocol IPX having similarities to IP SPX having similarities to TCP

15. IPX / SPX (cont..) Novell's UnixWare supported IPX/SPX natively. Open Enterprise Server – Linux: does not support IPX/SPX (have to use an additional software package) Open source FreeBSD OS includes an IPX/SPX stack

16. AppleTalk proprietary suite of protocols developed by Apple Inc. included in the original Macintosh released in 1984. corresponds closely to the Network layer

17. NETWORKING MODEL FOR AppleTalk OSI ModelCorresponding AppleTalk layers ApplicationApple Filing Protocol (AFP) PresentationApple Filing Protocol (AFP) Session Zone Information Protocol (ZIP), AppleTalk Session Protocol (ASP), AppleTalk Data Stream Protocol (ADSP) Transport AppleTalk Transaction Protocol (ATP), AppleTalk Echo Protocol (AEP), Name Binding Protocol (NBP), Routing Table Maintenance Protocol (RTMP) NetworkDatagram Delivery Protocol (DDP) Data link EtherTalk Link Access Protocol (ELAP), LocalTalk Link Access Protocol (LLAP) TokenTalk Link Access Protocol (TLAP), Fiber Distributed Data Interface (FDDI) PhysicalLocalTalk driver, Ethernet driver, Token Ring driver, FDDI driver

18. DLC (Down able Contents) is a form of digital media distributed through the Internet. used to refer specifically to content created for video games that is released separately from the main video game release. Or used to refer to any type of digital entertainment media distributed online. allowed users to download games using a telephone line or over the cable line.

19. DECnet a suite of network protocols created by Digital Equipment Corporation 1975 - peer-to-peer network architectures (built for 4 layers) 1980 - transforming DEC into a networking powerhouse 1982 - evolved into a 7 layer OSI compliant networking protocol 2010 - an open-source version has been developed for the Linux OS. DECnet code has been embedded in the Linux kernel

20. DECnet PHASE IV PROTOCOL SUITE LayersCorresponding Protocols Application DAP: Data Access Protocol CTERM: Command Terminal Network Management NICE: Network Information & Control Exchange MOP: Maintenance Operation Protocol SessionSCP: Session Control Protocol TransportNSP: Network Service Protocol NetworkDRP: DECnet Routing Protocol Data linkDDCMP: Digital Data Communications Message Protocol PhysicalEthernet, Token ring, FDDI,

21. NIC (Network Interface Card) is a hardware device that handles an interface to a computer network allows a network-capable device to access that network. has a ROM chip that contains a MAC Address exists on the Data Link Layer of the OSI model

22. NIC (Network Interface Card) 4 techniques NIC used to transfer data: Polling (microprocessor examines the status of the peripheral under program control) Programmed I/O (microprocessor alerts the designated peripheral by applying its address to the system's address bus) Interrupt-driven I/O (peripheral alerts the microprocessor that it's ready to transfer data) DMA (intelligent peripheral assumes control of the system bus to access memory directly - removes load from the CPU but requires a separate processor on the card)

23. COMMANDS… ping ifconfig dhclient

24. ping COMMAND is a computer network administration utility used to test the reach ability of a host on an Internet Protocol (IP) network to measure the round-trip time for messages sent from the originating host to a destination computer. operates by sending Internet Control Message Protocol (ICMP) echo request packets Used as a tool to troubleshoot problems in an IP network.

25. ifconfig COMMAND short for interface configuration It is a system administration utility in Unix-like operating systems to configure, control, and query TCP/IP network interface parameters originally appeared in 4.2BSD as part of the BSD TCP/IP suite. setting an interface's IP address and netmask, and disabling or enabling a given interface to display and analyze network interface parameters.