Configuring the Router
You will be able to learn the basic commands for configuring a router.
sh running-config – details the running configuration file (RAM)
sh startup-config – displays the configuration stored in NVRAM
setup – Will start the the automatic setup; the same as when you first boot the router
config t – use to execute configuration commands from the terminal
config mem – executes configuration commands stored in NVRAM; copies startup-config to running-config
config net – used to retrieve configuration info from a TFTP server
copy running-config startup-config – copies saved config in running config (RAM) to NVRAM or “write memory” for IOS under ver.11
copy startup-config running-config – copies from non-volatile (NVRAM) to current running config (RAM)
boot system flash
- tells router which IOS file in flash to boot from
boot system tftp – tells router which IOS file on the tftp server to boot from
boot system rom – tell router to boot from ROM at next boot
copy flash tftp – Copies flash to tftp server
copy tftp flash – Restores flash from tftp server
copy run tftp – Copies the current running-config to tftp server
copy tftp run – Restores the running-config from tftp server
General Commands
Here is a list of the general commands. These are the basic level commands and most commonly used
no shutdown – (enables the interface)
reload – restarts the router
sh ver – Cisco IOS version, uptime of router, how the router started, where system was loaded from, the interfaces the POST found, and the configuration register
sh clock – shows date and time on router
sh history – shows the history of your commands
sh debug – shows all debugging that is currently enabled
no debug all – turns off all debugging
sh users – shows users connected to router
sh protocols – shows which protocols are configured
banner motd # Your customized message here # – Set/change banner
hostname – use to configure the hostname of the router
clear counters – clear interface counters
Privileged Mode commands of a router
Learn how to work in the privileged mode of a router.
enable – get to privileged mode
disable – get to user mode
enable password – sets privileged mode password
enable secret – sets encrypted privileged mode password
Setting Passwords on router
Here you will be able to learn how to set the password on a router.
enable secret – set encrypted password for privileged access
enable password – set password for privileged access (used when there is no enable secret and when using older software)
Setting the password for console access:
(config)#line console 0
(config-line)#login
(config-line)#password
Set password for virtual terminal (telnet) access (password must be set to access router through telnet):
(config)#line vty 0 4
(config-line)#login
(config-line)#password
Set password for auxiliary (modem) access:
(config)#line aux 0
(config-line)#login
(config-line)#password
Router Processes & Statistics
By these command you can see the statistics and different processes of the router.
sh processes – shows active processes running on router
sh process cpu – shows cpu statistics
sh mem – shows memory statistics
sh flash – describes the flash memory and displays the size of files and the amount of free flash memory
sh buffers – displays statistics for router buffer pools; shows the size of the Small, Middle, Big, Very Big, Large and Huge Buffers
sh stacks – shows reason for last reboot, monitors the stack use of processes and interrupts routines
IP Commands
Here is a list of the IP Commands
Configure IP on an interface:
int serial 0
ip address 157.89.1.3 255.255.0.0
int eth 0
ip address 2008.1.1.4 255.255.255.0
Other IP Commands:
sh ip route – view ip routing table
ip route [administrative_distance] – configure a static IP route
ip route 0.0.0.0 0.0.0.0
- sets default gateway
ip classless – use with static routing to allow packets destined for unrecognized subnets to use the best possible route
sh arp – view arp cache; shows MAC address of connected routers
ip address 2.2.2.2 255.255.255.0 secondary – configure a 2nd ip address on an interface
sh ip protocol
CDP Commands (Cisco Discovery Protocol uses layer 2 multicast over a SNAP-capable link to send data):
sh cdp neighbor – shows directly connected neighbors
sh cdp int – shows which interfaces are running CDP
sh cdp int eth 0/0 – show CDP info for specific interface
sh cdp entry – shows CDP neighbor detail
cdp timer 120 – change how often CDP info is sent (default cdp timer is 60)
cp holdtime 240 – how long to wait before removing a CDP neighbor (default CDP holdtime is 180)
sh cdp run – shows if CDP turned on
no cdp run – turns off CDP for entire router (global config)
no cdp enable – turns off CDP on specific interface
IPX Commands
Enable IPX on router:
ipx routing
Configure IPX + IPX-RIP on an int:
int ser 0
ipx network 4A
Other Commands:
sh ipx route – shows IPX routing table
sh ipx int e0 – shows ipx address on int
sh ipx servers – shows SAP table
sh ipx traffic – view traffic statistics
debug ipx routing activity – debugs IPS RIP packets
debug ipx sap – debugs SAP packets
Routing Protocols
RIP, IGPR and OSPF are the routing protocols and here is a list of the commands for the working on the routing protocols.
Configure RIP:
router rip
network 157.89.0.0
network 208.1.1.0
Other RIP Commands:
debug ip rip – view RIP debugging info
Configure IGRP:
router IGRP 200
network 157.89.0.0
network 208.1.1.0
Other IGRP Commands:
debug ip igrp events – view IGRP debugging info
debug ip igrp transactions – view IGRP debugging info
Access Lists
Here is a list of the Access list command of a router.
sh ip int ser 0 – use to view which IP access lists are applies to which int
sh ipx int ser 0 – use to view which IPX access lists are applies to which int
sh appletalk int ser 0 – use to view which AppleTalk access lists are applies to which int
View access lists:
sh access-lists
sh ip access-lists
sh ipx access-lists
sh appletalk access-lists
Apply standard IP access list to int eth 0:
access-list 1 deny 200.1.1.0 0.0.0.255
access-list 1 permit any
int eth 0
ip access-group 1 in
Apply Extended IP access list to int eth 0:
access-list 100 deny tcp host 1.1.1.1 host 2.2.2.2 eq 23
access-list 100 deny tcp 3.3.3.0 0.0.0.255 any eq 80
int eth 0
ip access-group 100 out
Apply Standard IPX access list to int eth 0:
access-list 800 deny 7a 8000
access-list 800 permit -1
int eth 0
ipx access-group 800 out
Apply Standard IPX access list to int eth 0:
access-list 900 deny sap any 3378 -1
access-list 900 permit sap any all -1
int eth 0
ipx access-group 900 out
WAN Configurations Commands
Networking over WAN is the main functionality of a router. The most common use of a router is for the WAN connectivity. Here is a list of the commands for the different methods of the WAN connectivity.
PPP Configuration
Point to point protocol is a method for the WAN connectivity and you will find here some commands of PPP.
encapsulation pppppp authentication
ppp chap hostname
ppp pap sent-username
sh int ser 0 – use to view encapsulation on the interface
Frame-Relay Configuration
One of the methods for the WAN connectivity is the Frame Relay. Find here some basic commands for the WAN connectivity through Frame Relay.
encapsulation frame-relay ietf – use IETF when setting up a frame-relay network between a Ciscorouter and a non-Cisco router
frame-relay lmi-type ansi – LMI types are Cisco, ANSI, Q933A; Cisco is the default; LMI type is auto-sensed in IOS v11.2 and up
frame-relay map ip 3.3.3.3 100 broadcast – if inverse ARP won’t work, map Other IP to Your DLCI # (local)
keep alive 10 – use to set keep alive
sh int ser 0 – use to show DLCI, LMI, and encapsulation info
sh frame-relay pvc – shows the configured DLCI’s; shows PVC traffic stats
sh frame-relay map – shows route mapssh frame-relay lmi – shows LMI info
Miscellaneous Commands
In the last but not least here is a list of the some miscellaneous and useful commands
sh controller t1 – shows status of T1 lines
sh controller serial 1 – use to determine if DCE or DTE device
(config-if)#clock rate 6400 – set clock on DCE (bits per second)
(config-if)#bandwidth 64 – set bandwidth (kilobits)





























