1 © 2003, Cisco Systems, Inc. All rights reserved. CCNA 2 v3.0 Module 1 WANs and Routers Presented by: Terren L. Bichard

222 © 2003, Cisco Systems, Inc. All rights reserved. Objectives WANs Routers

333 © 2003, Cisco Systems, Inc. All rights reserved. Introduction to WANs A wide-area network (WAN) is a data communications network spanning a large geographic area such as a state, province, or country. –WANs function at the Physical and Data Link Layers of the OSI model.

444 © 2003, Cisco Systems, Inc. All rights reserved. Major Characteristics of WANs They connect devices that are seperated by wide geographical areas. They use the services of carriers such as the Regional Bell Operating Companies. Sprint, MCI, VPM Internet Services, Inc., and Altantes.net They use serial connections of various types to access bandwidth over large geographic areas.

555 © 2003, Cisco Systems, Inc. All rights reserved. WANs vs. LANs WANs makes data connections across a broad geographic area. WANs connect LANs. WANs provide for the exchange of data packets and frames between routers and switches and the LANs they support. Operate at the Layers 1 & 2 of the OSI Model LANs connect workstations, peripherals, terminals and other devices in a single building or other small geographic area.

666 © 2003, Cisco Systems, Inc. All rights reserved. WAN Devices

777 © 2003, Cisco Systems, Inc. All rights reserved. Routers Offer many services including Internetworking and WAN Interface ports

888 © 2003, Cisco Systems, Inc. All rights reserved. WAN Switches Provide connectivity for Voice Data Video communication

999 © 2003, Cisco Systems, Inc. All rights reserved. Modems Include interface voice-grade services, channel service units/digital service units (CSU/DSU) that interface T1/E1 services, and Terminal Adapters/Network Termination 1 that interface ISDN services.

10 © 2003, Cisco Systems, Inc. All rights reserved. Communication Servers Concentrate dial-in and dial-out user communication. (Do Interactive Activity 1.1.1)

11 © 2003, Cisco Systems, Inc. All rights reserved. Intro. To Routers Special type of computer Same basic components as a PC –CPU, memory, system bus, I/O interfaces Connect and allow communication between two networks and determine the best path for packets to travel. Have OS just like PCs to run config files.

12 © 2003, Cisco Systems, Inc. All rights reserved. Internal Configuration Components

13 © 2003, Cisco Systems, Inc. All rights reserved. RAM Stores Routing Tables Holds ARP Cache Holds fast-switching cache Performs packet buffering (shared RAM) Maintains packet-hold queues Provides temporary memory for the config files while the router is powered on Loses its content when powered down or restarted

14 © 2003, Cisco Systems, Inc. All rights reserved. NVRAM (Non-Volatile RAM) Provides storage for the startup configuration file. Retains its content when the router is powered down or restarted.

15 © 2003, Cisco Systems, Inc. All rights reserved. Flash Memory Holds the operating system image (IOS) Allows software to be updated without removing and replacing chips on the processor Retains content when router is powered down or restarted Can store multiple versions of IOS software Is a type of electronically erasable, programmable ROM (EEPROM)

16 © 2003, Cisco Systems, Inc. All rights reserved. Read-only memory (ROM) Maintains instructions for power-on self test (POST) diagnostics Stores bootstrap program and basic operating system software Requires replacing pluggable chips on the motherboard for software upgrades

17 © 2003, Cisco Systems, Inc. All rights reserved. Interfaces Connect router to network for frame entry and exit Can be “fixed” on the motherboard or on a separate module

18 © 2003, Cisco Systems, Inc. All rights reserved. Three Types of Interfaces LAN Interfaces –Ethernet or Token Ring WAN Interfaces –Serial, ISDN, Fixed or modular Management Interfaces –Console/AUX Asynchronous Serial ports used primarily for configuration –Initial or terminal sessions Management Interfaces not network interfaces

19 © 2003, Cisco Systems, Inc. All rights reserved. Router External Connections

20 © 2003, Cisco Systems, Inc. All rights reserved. External Connections on a 2600 Router

21 © 2003, Cisco Systems, Inc. All rights reserved. Power Supply Provide necessary power to operate the internal components –May be multiple and/or modular (Do Interactive Media Labs)

22 © 2003, Cisco Systems, Inc. All rights reserved. Internal Components of a 2600 Router

23 © 2003, Cisco Systems, Inc. All rights reserved. Router LANs and WANs Routers may be used to segment LANs but primary use is as a WAN device. Have both WAN and LAN interfaces –Serial and Ethernet

24 © 2003, Cisco Systems, Inc. All rights reserved. Main function of Router Best Path Determination Switching of Frames –Done using Routing Tables –Sharing information with other routers Tables are updated dynamically using routing protocol

25 © 2003, Cisco Systems, Inc. All rights reserved. Internetwork Routers Any internetwork must include the following: Consistent end-to-end addressing Addresses that represent network topologies Best path selection Dynamic routing Switching

26 © 2003, Cisco Systems, Inc. All rights reserved. Router’s Role in a WAN Operates at Physical and Data-Link Layers –Standards and protocols in WANs are different than those used in LANs at the same layers.

27 © 2003, Cisco Systems, Inc. All rights reserved. WAN Physical Layer Standards & Protocols EIA/TIA-232 EIA/TIA-449 V.24 V.35 X.21 G.703 EIA-530 ISDN T1, T3, E1, E3 xDSL SONET (OC-3, OC-12, OC-48, OC-192

28 © 2003, Cisco Systems, Inc. All rights reserved. WAN Data Link Layer Standards & Protocols High-level data link control (HDLC) Frame Relay Point-to-Point (PPP) Synchronous Data Link Control (SDLC) Serial Line Internet Protocol (SLIP) X.25 ATM LAPB LAPD LAPF

29 © 2003, Cisco Systems, Inc. All rights reserved. Data Link Encapsulations

30 © 2003, Cisco Systems, Inc. All rights reserved. WAN The WAN physical layer describes the interface between the DTE and the DCE –DTE is usually the Router –DCE is the service provider

31 © 2003, Cisco Systems, Inc. All rights reserved. WAN Services

32 © 2003, Cisco Systems, Inc. All rights reserved. Connection of Console Interfaces Console port –Management port used to provide out-of-band access to the router –Used for initial configuration of router Must be directly connected to router to do initial config. –Monitoring –Disaster and password recovery procedures –Preferred over AUX port Displays router startup, debugging and error messages by default.

33 © 2003, Cisco Systems, Inc. All rights reserved. To Connect the PC to a Router Configure terminal emulation software on the PC for: –Appropriate com port (com1 or com2) –9600 baud –8 data bits –No parity –1 stop bit –No flow control

34 © 2003, Cisco Systems, Inc. All rights reserved. To Connect the PC to a Router Connect RJ-45 connector of the rollover cable to the router console port. Connect other end of rollover cable to Terminal adapter (RJ-45 to DB-9) Attach the female DB-9 adapter to a PC.

35 © 2003, Cisco Systems, Inc. All rights reserved. Computer or Terminal Console Connection (Do Lab)

36 © 2003, Cisco Systems, Inc. All rights reserved. Modem Connection to Console or Auxiliary Port

37 © 2003, Cisco Systems, Inc. All rights reserved. Connecting LAN Interfaces

38 © 2003, Cisco Systems, Inc. All rights reserved. Academy Approach to Labs In the academy lab, all the networks will be connected with serial or Ethernet cables and the students can see and physically touch all the equipment. Devices that make up the WAN cloud are simulated by the connection between the back-to-back DTE-DCE cables.

39 © 2003, Cisco Systems, Inc. All rights reserved. Router Serial WAN Connectors

40 © 2003, Cisco Systems, Inc. All rights reserved. DCE Serial Connections

41 © 2003, Cisco Systems, Inc. All rights reserved. SUMMARY WAN & LAN concepts Role of a router in WANs and LANs WAN Protocols Configuring encapsulation Identification and description of the internal components of a router Physical characteristics of a router Common ports on a router How to connect router console, LAN and WAN ports