Cisco Router

Overview Understanding and configuring the Cisco Internetwork Operating System (IOS) Connecting to a router Bringing up a router Logging into a router Understanding the router prompts Understanding the CLI prompts

Overview Performing editing and help features Gathering basic routing information Setting administrative functions Setting hostnames Setting banners Setting passwords

Overview Setting interface descriptions Performing interface configurations Viewing, saving, and erasing configurations Verifying routing configurations

Cisco Router Router uses to connect: -  Subnet with another Subnet (By LAN Interface).  LAN with another LAN (By WAN Interface).  LAN with WAN (By WAN Interface).  WAN with another WAN (By WAN Interface). Router Consist of External Components (Interfaces) and Internal Components

Cisco Router IOS The Cisco IOS (Internetwork Operating System) was created to deliver network services and enable networked applications. It runs on most Cisco routers. Some of the important things that the Cisco router IOS software is responsible for include  Carrying network protocols and functions.  Connecting high-speed traffic between devices.  Adding security to control access and stop unauthorized network use.  Supplying network reliability for connecting to network resources.

Connecting to a Cisco Router You can connect to a Cisco router to configure it, verify its configuration, and check statistics. There are Three ways to do that: -  Console Session.  Auxiliary Session.  Telnet Session can’t use this method after router has taken valid IP address.

Bringing Up a Router When you first bring up a router, it will takes this Boot Sequence: - 1.Perform POST (Power On Self Test) which is small program stored in ROM to check router components. 2.Load IOS image from Flash memory and decompress it into RAM. 3.Display the information from POST. 4.Running Valid Configuration ( Startup Conf ). 5.If no configuration router will go into Setup mode.

Setup Mode You have two options when using setup mode: - 1.Basic Management only gives you enough configurations to allow connectivity to the router. 2.Extended Setup gives you the power to configure some global parameters as well as interface configuration parameters.

Command-Line Interface Because it’s so much more flexible, the command-line interface (CLI) truly is the best way to configure a router. Logging into the Router Router> ---> User Mode (used to view statistics) Router>enable Router# ---> Privileged Mode (used to view and change configuration) You can go back from privileged mode into user mode by using the disable command. Router#disable Router>

Overview of Router Modes To configure from a CLI, you can make global changes to the router by typing configure terminal (or config t for short). Router#config Configuring from terminal, memory, or network [terminal]? [Enter] Enter configuration commands, one per line. End with CNTL/Z. Router(config)# Terminal -----> means any changes in router configuration made in DRAM (Dynamic RAM). Memory -----> means any changes in router configuration made in NVRAM (Startup Config). Network -----> means any changes in router configuration made in TFTP or FTP Server.

CLI Prompts Interfaces To make changes to an interface, you use the interface command from global configuration mode: Router(config)#interface fastethernet 0/0 Router(config-if)# Line Commands To configure user-mode passwords, use the line command. The prompt then becomes: Router#config t Enter configuration commands, one per line. End with Ctrl+Z Router(config)#line console 0 Router(config-line)# The line console 0 command is known as a major command (also called a global command). Any command typed from the (config-line) prompt is known as a subcommand.

CLI Prompts Routing Protocol Configurations To configure routing protocols such as RIP and IGRP, use the prompt (config-router)#: Router#config t Enter configuration commands, one per line. End with CNTL/Z. Router(config)#router rip Router(config-router)# Editing and Help Features You can use the Cisco advanced editing features to help you configure your router by typing (?) Router#?

Router Administrative Functions Hostnames You can set the identity of the router with the hostname command. Router#config t Router(config)#hostname R R(config)# Banners It gives a message to every person dialing into or connecting to the router via Telnet or auxiliary port, or even through a console port as seen here: Router(config)#banner motd $ Enter TEXT message. End with the character ‘$'. ###### This router For Orbits Co. ###### $

Router Administrative Functions Setting Passwords 1. Enable Passwords Router(config)#enable ? password Assign the privileged level password secret Assign the privileged level secret 2. Auxiliary Password Router(config)#line aux 0 Router(config-line)#password ahmed 3. Console Password Router(config)#line console 0 Router(config-line)# password ahmed1

Router Administrative Functions 4. Telnet Password Router(config-line)#line vty 0 4 Router(config-line)# password ahmed2 Encrypting Your Passwords Because only the enable secret password is encrypted by default, you’ll need to manually configure the user-mode and enable passwords for encryption. Router#sh run Router(config)#service password-encryption Router(config)#no service password-encryption (To cancel previous command) Descriptions Setting descriptions on an interface is helpful to the administrator. Router(config)#int f0/0 Router(config-if)#desc Sales Lan

Router Interfaces Interface configuration is one of the most important router configurations, because without interfaces, a router is pretty much a completely useless object. Router#conf t Router(config)#int f0/0 To Configure any router interface, there are two mainly steps 1. Bringing up interface Router(config-if)#no shut 2. Assign an IP address Router(config-if)#ip address Serial Interface Commands serial interfaces like any router interface, but if that DCE (data Circuit Equipment). It takes additional command. Router(config)#int s0/0 Router(config-if)#no shut Router(config-if)#ip address Router(config-if)#clock rate 64000

Viewing, Saving, and Erasing Configurations You can manually save the file from DRAM to NVRAM by using the copy runningconfig startup-config command Router#copy run start You can view the files by typing show running-config or show startup-config from privileged mode. Router#sh run Router#sh start You can delete the startup-config file by using the erase startup- config command. Router#erase start

Viewing, Saving, and Erasing Configurations Verifying Your Configuration 1. By using ping command Router#ping By using Show command Router#sh int f0/0 3. By using sh ip int command The show ip interface command will provide you with information regarding the layer 3 configurations of a router’s interfaces: Router#sh ip int 4. By using sh ip int brief command Router#sh ip int brief 5. By using sh controllers command Router#sh controllers serial 0/0 buffer size 1524 HD unit 0, V.35 DTE cable