Configuring a Router

Understanding LED indicators on the routerThis green light means that the system is on and has initialized properly.An interface LED indicates the activity of the corresponding interface.A problem may be indicated if an LED is off

CLI Command Modes

Basic Steps to Configure a RouterConfigure hostnameConfigure passwords Enable / enable secretConsole Virtual terminal (vty)Configure interfacesConfigure routing protocol

Configuring the Router HostnameRouter#config tRouter(config)#hostname Router_ARouter_A(config)#exitRouter_A#

Password ConfigurationPasswords are set for:privileged EXEC modeEnable password (not used if secret password is set)Enable secret password (restricts going from user to privileged)line passwordsconsole interfaceVTY or virtual terminals

Password ConfigurationSetting Passwords are set for:privileged EXEC modeEnable password Router(config)#enable password passwordEnable secret password Router(config)#enable secret password

Password ConfigurationSetting Passwords are set for:line passwordsconsole interfaceRouter(config)#line console 0Router(config-line)#password passwordRouter(config-line)#login VTY or virtual terminalsRouter(config)#line vty 0 4Router(config-line)#password passwordRouter(config-line)#login

Password ConfigurationPassword Encryption may setThe service password-encryption command may be used to set passwords to not display in clear text when viewing running configuration.Router(config)#line console 0Router(config-line)#password passwordRouter(config-line)#login Router(config-line)#service password-encryptionSecret password is always encrypted even when the command above is not used

Password ConfigurationIf no password is set for virtual terminal sessions, no one can log into the router using a virtual terminal session

show commandsshow interfaces stats on the router interfacesshow controllers serial hardware info re serial interfacesshow clock Shows the time set in the router show hosts Displays a cached list of host names and addresses show users Displays all users who are connected to the router show history history of commandsshow flash info about flash memory and the IOSs stored there

show commandsshow version info about router and IOS running in RAM show ARP Displays the ARP table of the router show protocol Displays the global and interface specific status of any configured Layer 3 protocols show startup-configuration Displays the saved configuration located in NVRAM show running-configuration Displays the configuration currently running in RAM

Login BannersThey are seen by everyone (telnet, AUX port, console port)Can convey message to all usersMight want to include a warning not to access the deviceUse a delimiting character before and afterRouter#config tRouter(config)#banner motd # Authorized Users Only!!! #