1. 1 CCNA 2 v3.1 Module 1 WANs & Routers

2. 222 Wide Area Network Characteristics It is a data communications network Connect devices separated by wide geographical area state, province, or country Use the services of carrier providers Regional Bell Operating Companies (RBOCs), Sprint, MCI, VPM Internet Services, Inc., and Altantes.net. Use serial connections to access bandwidth

3. 333 How do WANs differ from LANs WAN data connections across a broad geographic area connect company sites so that information can be exchanged between distant offices Interconnect LANs Exchange data packets and frames between routers and switches and the LANs they support What layer do WANs operate at Datalink layer (2) Physical layer (1)

4. 444 WAN Devices Routers Connect two networks Allow communication between two networks Determine the best path for data to travel Switches provide connectivity for voice, data, and video Modems Interface voice-grade services Channel service units/digital service units (CSU/DSUs) that interface T1/E1 services Terminal Adapters/Network Termination 1 (TA/NT1s) that interface Integrated Services Digital Network (ISDN) services. Communication servers concentrate dial-in and dial-out user communication

5. 555 WAN DataLink layer Protocols Describe how frames are carried between systems on a single data link Protocols designed to operate over Dedicated point-to-point link Multipoint link Multi-access switched services (Frame Relay)

6. 666 WAN Standards Authroities International Telecommunication Union- Telecommunication Standardization Sector (ITU-T) formerly the Consultative Committee for International Telegraph and Telephone (CCITT) International Organization for Standardization (ISO) Internet Engineering Task Force (IETF) Electronic Industries Association (EIA)

7. 777 Router Components

8. 888 CPU The Central Processing Unit (CPU) microprocessor Executes operating system instructions System initialization Routing functions Network interface control Large routers may have multiple CPUs

9. 999 RAM Dynamic RAM (DRAM) Can be upgraded using Dual In-Line Memory Modules (DIIMS Stores routing tables Running configuration – temporarily while router is on ARP cache Performs packet buffering – packet queues Maintains packet-hold queues Run time space for executable Cisco IOS software Volatile – power fails information is lost Divided into Main processor memory Shared input/output (I/O) memory Shared among interfaces for temporary storage of packets

10. 10 NVRAM Non-Volatile Random-Access Memory Provides storage for the startup/backup configuration file Non-volatile Retains information when router is powered down or restarted

11. 11 Flash Memory Electronically erasable, programmable ROM (EEPROM) Holds full copy of operating system image (IOS) Default settings for IOS is flash Can be in compressed or uncompressed format Executable copy of IOS transferred to RAM during boot up Can store multiple versions of IOS IOS software can updated without removing and replacing chips on the processor Volatile To add or replace flash Single In-Line Memory Modules (SIMMs) PCMCIA cards can upgrade the amount of flash

12. 12 ROM Permanently stores startup diagnostic code ROM Monitor Hardware diagnositics - power-on self test (POST) Stores bootstrap program Loads CISCO IOS software from flash to RAM Not erasable Can only be upgraded by replacing the ROM chips in the sockets of the motherboard

13. 13 Bus System Bus Used to transfer packets between the CPU and the interfaces CPU Bus Used by the CPU to transfers instructions and data to or from specified memory addresses Power Supply Provides necessary power to operate the internal components Larger routers use multiple or modular power supplies

14. 14 Interfaces Router connections to the outside Types of interfaces LAN interfaces Either ethernet or token ring connections WAN interfaces Serial, ISDN, and Integrated Channel Service Unit (CSUs Console / Auxilary Serial port used for initial configuration of the router Used for terminal sessions from coms port on computer LAN and WAN configurations can be Fixed – E1, E0, S1, S0 Modular – Fastethernet 0/0, Fastethernet 0/1, serial 0/1, serial 0/0

15. 15 Routers for Segmenting LAN Routers operate at the network layer (3) They make decisions based on IP addresses Divide networks into smaller collision domains Divide networks into smaller broadcast domains

16. 16 Routers have both LAN and WAN Connections

17. 17 Making decisions based on network addresses To determine the network address AND subnet mask and destination ip address Router functions Routers select the best path Routers switch the frames to the proper interface How do routers accomplish this Building routing tables Exchanging network information with other routers

18. 18 Routing tables are maintained Statically by administrator Dynamically by routing protocols exchanging topology information A correctly configured internetwork provides Consistent end-to-end addressing Addresses that represent network topologies Best path selection Dynamic or static routing Switching

19. 19 Routers Role in WAN WAN physical layer describes the interface between DTE and DCE

20. 20 Routers Operate as both LAN and WAN devices Can exclusively be a LAN or WAN device LAN – L1, L2, L3 WAN – L1, L2 Can sit at the boundary between a LAN and a WAN LAN and WAN device at the same time

21. 21 WAN physical layer standards and protocols: EIA/TIA-232, EIA/TIA-449 V.24, V.35, X.21 G.703, EIA-530 ISDN, T1, T3, E1, and E3 xDSL, SONET (OC-3, OC-12, OC-48, OC-192) WAN data link layer standards and protocols: High-level data link control (HDLC) Frame Relay Point-to-Point Protocol (PPP) Synchronous Data Link Control (SDLC) Serial Line Internet Protocol (SLIP) X.25, ATM, LAPB, LAPD, LAPF Try the interactive media lab 1.1.5

22. 22 Internal Components of 2600 Router

23. 23 External Components of 2600 Router

24. 24 LAN interfaces Allow the router to connect to the Local Area Network media Usually some form of Ethernet (could be Token Ring) Wide Area Network connections Provide connections through a service provider to a distant site Management Connections Console Port or Auxiliary Port

25. 25 Configuration through Console Port

26. 26 Used for Initial router configuration Monitoring Disaster recovery procedures (password recovery) Console port is preferred for troubleshooting It displays router startup, debugging, error messages by default Used when networking services have not been started/ failed Console Port

27. 27 In order to configure a Router Terminal must support VT100 terminal emulation HyperTerminal Configure terminal emulation software on the PC for: The appropriate com port 9600 baud 8 data bits No parity 1 stop bit No flow control

28. 28 Modem Connection to Auxiliary Port Used to configure router from a remote connection

29. 29 Connecting LAN Interfaces Ethernet Connection – E0, E1 Fast Ethernet Connection – FastEthernet 0/0 Router communicates with LAN Via a hub or switch Crossover cable used to connect router Ethernet connection directly to a computer or another router Straight Through Cable

30. 30 WAN Connection Types