Router modes Modes Description Router> User mode Router# Privileged mode Router(config)# Global configuration mode Router(config...
Router modes
| Modes | Description |
| Router> | User mode |
| Router# | Privileged mode |
| Router(config)# | Global configuration mode |
| Router(config-if)# | Interface mode |
Basic IOS Commands
| Command | Description | Syntax |
| Enable | Puts you into privileged mode | Router>enable |
| Disable | Takes you from privileged mode back to user mode | Router>disable |
| Config Terminal | Puts you in global configuration mode and change the running-config | Router#config t |
| Hostname | Sets the name of a router | Router(config)#hostname R1 |
| Banner | Creates a banner for users who log into the router | Router(config)#banner motd # |
| Enable Password | Sets the encrypted enable password | Router(config)#enable password |
| Enable Secret | Sets the encrypted enable secret. Supersedes the enable password if set | Router(config)#enable secret |
| Line Aux | Puts in the auxiliary interface configuration mode | Router(config)#line aux 0 Router(config-line)#login Router(config)# password cisco |
| Line Console 0 | Puts you in the console configuration mode | Router(config)#line console 0 Router(config-line)#login Router(config)# password cisco |
| Line Vty | Puts you in VTY (Telnet) interface configuration mode | Router(config-line)#line vty 0 4 Router(config-line)#login Router(config)# password cisco |
| Service Password-encryption | Encrypts the user mode and enable password | Router(config)#service password-encryption |
| Terminal History Size | Changes your history size from the default of 10 up to 256 | Router#terminal history size 25 |
| Telnet | Tests IP connectivity and configures a router | Telnet [destination ip] Router#telnet 172.16.10.2 |
| Ping | Tests IP connectivity | Ping [destination ip] Router#ping 172.16.10.2 |
| Interface Fastethernet 0/0 | Puts you in interface configuration mode for a fastethernet port | Router(config)#int fa 0/0 |
| Interface Serial 1 | Puts you in configuration mode for interface serial 1 and can be used for show commands | Router(config)#int serial 1 |
| Ip Address | Sets an IP address on an interface | Router(config)#ip address 172.16.10.2 255.255.255.0 |
| Bandwidth | Sets the bandwidth on a serial interface | Router(config-if)#bandwidth 64 |
| Copy Run Start | Short for copy running-config, startup-config. Places a configuration into NVRAM | Router#copy run start |
| Erase Startup | Deletes the startup-config | Router#erase startup-config |
| Show Controllers S 0 | Show the DTE or DCE status of an interface | Router#sh controllers s 0 |
| Show History | Shows you the last 10 commands entered by default | Router#sh history |
| Show Interface S 0 | Shows the statistics of interface serial 0 | Router#sh int s 0 |
| Show Run | Short for show running-config. Shows the configuration currently running on the router | Router#sh run |
| Show Start | Short for show startup-config. Shows the backup configuration stored in NVRAM | Router#sh start |
| Show Terminal | Shows you your configured history size | Router#sh terminal |
| Show Version | Shows you statistic of the router | Router#sh ver |
| Shutdown | Puts an interface in administratively-down mode | Router(config-if)#shutdown |
IP Routing Commands
| Command | Description | Syntax |
| Ip route | Creates static and default routes on a router | Ip route [destination_network] [mask] [next_hop_address or exitinterface] [administrative_distance] [permanent] Example: Router(config)#ip route 172.16.20.0 255.255.255.0 172.16.10.2 |
| No ip route | Removes a static default rout | Router(config)#no ip route 172.16.20.0 255.255.255.0 172.16.10.2 |
| Router RIP | Turns on ip rip routing on a router | Router(config)#router rip |
| Network | Tells the routing protocol what network to advertise | Router(config-if)#network 172.16.20.0 |
| Router igrp AS | Turns on ip igrp routing on a router | Router igrp[Autonomous system no.] Router(config)#router igrp 10 |
| Debug ip rip | Sends console messages displaying information about rip packets being sent and received on a router interface | Router#debug ip rip |
| Debug ip igrp events | Provides a summary of the igrp routing information running on the network | Router#debug ip igrp events |
| Debug ip igrp transactions | Shows message requests from neighbor routes asking for an update and the broadcast sent from your router to that neighbor router | Router#debug ip igrp transactions |
| Show ip route | Displays the ip routing table | Router#sh ip route |
| Show protocols | Shows the routed protocols and network addresses configured on each interface | Router#sh protocols |
| Show ip protocols | Shows the routing protocols and timers associated with each routing protocol configured on a router | Router#sh ip protocols |
Managing Internetwork
| Command | Description | Syntax |
| Cdp enable | Turns on cdp on an individual interface | Router#cdp enable |
| No cdp enable | Turns off cdp on an individual interface | Router#no cdp enable |
| Cdp run | Turns on cdp on a router | Router#cdp run |
| No cdp run | Turns off cdp completely on router | Router#no cdp run |
| Cdp holdtime | Changes the holdtime of cdp packets | Router(config)#cdp holdtime 240 |
| Cdp timer | Changes the cdp update timer | Router(config)#cdp timer 90 |
| Clear line | Clears a connection connected via telnet to your router | Router#clear line 2 |
| Config-register | Tells the router how to boot and to change the configuration register setting | Router(config)#config-register 0x0101 |
| Copy flash tftp | Copies a file from flash memory to a tftp host | Router# copy flash tftp |
| Copy run start | Copies the running-config file to the startup-config file | Router#copy run start |
| Copy run tftp | Copies the running-config file to a tftp host | Router#copy run tftp |
| Copy tftp flash | Copies a file from a tftp host to flash memory | Router#copy tftp flash |
| Copy tftp run | Copies a configuration from a tftp host to the running-config file | Router#copy tftp run |
| Erase startup-config | Deletes the contents of NVRAM on a router | Router#erase startup-config |
| Ip host | Creates a host table on a router | Ip host[hostname] [ip address] Example: Router(config)#ip host router2 172.16.10.2 |
| No ip host | Removes a hostname from a host table | Router(config)#no ip host router2 172.16.10.2 |
| Show cdp | Displays the cdp timer and holdtime frequencies | Router#sh cdp |
| Show cdp entry | Same as show cdp neighbor detail, but does not work on a 1900 switch | Router#sh cdp entry |
| Show cdp interface | Shows the individual interfaces enabled with cdp | Router#sh cdp interface |
| Show cdp neighbor | Shows the directly connected neighbors and the details about them | Router#sh cdp nei |
| Show cdp neighbor detail | Shows the ip address and IOS version and type, and includes all of the information from the show cdp neighbor command | Router#sh cdp neighbor detail |
| Show cdp traffic | Shows the cdp packets sent and received on a device and any errors | Router#sh cdp traffic |
| Show flash | Shows the files in flash memory | Router#sh flash |
| Show hosts | Shows the contents of the host table | Router#sh hosts |
| Show sessions | Shows your connections via telnet to remote device | Router#sh sessions |
