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»Cisco Forum FAQ »The most straight-forward way to configure Cisco router: Introduction to CLI

CCNA level Cisco Commands and Descriptions

Following is a list of commands that are applicable to most IOS-based equipments such as routers and switches. Check out the following links for full commands.

IOS Commands 12.4 version on Routers
IOS and Catalyst OS Commands on 6500 series Switches
IOS Commands 12.2 version on 4500 series Switches
IOS Commands 12.2 version on 3560 series Switches
ASA and PIX Firewall OS Commands 6.2 version and above

? Gives you a help screen A wildcard command; same as the any command

access-class Applies a standard IP access list to a VTY line

access-list Creates a list of tests to filter the networks 9

any Specifies any host or any network; same as the command

Backspace Deletes a single character

bandwidth Sets the bandwidth on a serial interface

banner Creates a banner for users who log into the router

cdp enable Turns on CDP on an individual interface

cdp holdtime Changes the holdtime of CDP packets

cdp run Turns on CDP on a router

cdp timer Changes the CDP update timer

clear counters Clears the statistics from an interface

clear line Clears a connection connected via Telnet to your router

clear mac-address-table Clears the filter table created dynamically by the switch

clock rate Provides clocking on a serial DCE interface

config memory Copies the startup-config to running-config

config network Copies a configuration stored on a TFTP host to running-config

config terminal Puts you in global configuration mode and changes the running-config

config-register Tells the router how to boot and to change the configuration register setting

copy flash tftp Copies a file from flash memory to a TFTP host

copy run start Short for copy running-config startup-config; places a configuration into NVRAM

copy run tftp Copies the running-config file to a TFTP host

copy tftp flash Copies a file from a TFTP host to flash memory

copy tftp run Copies a configuration from a TFTP host to the running-config file

Ctrl+A Moves your cursor to the beginning of the line

Ctrl+D Deletes a single character

Ctrl+E Moves your cursor to the end of the line

Ctrl+F Moves forward one character

Ctrl+R Redisplays a line

Ctrl+Shift+6, then X (keyboard combination) Returns you to the originating router when you telnet to numerous routers

Ctrl+U Erases a line

Ctrl+W Erases a word

Ctrl+Z Ends configuration mode and returns to EXEC

debug dialer Shows you the call setup and teardown procedures

debug frame-relay lmi Shows the lmi exchanges between the router and the Frame Relay switch

debug ip igrp events Provides a summary of the IGRP routing information running on the network

debug ip igrp transactions Shows message requests from neighbor routers asking for an update and the broadcasts sent from your router to that neighbor router

debug ip rip Sends console messages displaying information about RIP packets being sent and received on a router interface

debug ipx Shows the RIP and SAP information as it passes through the router

debug isdn q921 Shows layer-2 processes

debug isdn q931 Shows layer-3 processes

delete nvram Deletes the contents of NVRAM on a 1900 switch

delete vtp Deletes VTP configurations from a switch

description Sets a description on an interface

dialer idle-timeout number Tells the BRI line when to drop if no interesting traffic is found

dialer list number protocol protocol permit/deny Specifies interesting traffic for a DDR link

dialer load-threshold number inbound/outbound/either Sets the parameters that describe when the second BRI comes up on an ISDN link

dialer map protocol address name hostname number Used instead of a dialer string to provide more security in an ISDN network

dialer string Sets the phone number to dial for a BRI interface

disable Takes you from privileged mode back to user mode

disconnect Disconnects a connection to a remote router from the originating router

duplex Sets the duplex of an interface

enable Puts you into privileged mode

enable password Sets the unencrypted enable password

enable password level 1 Sets the user mode password

enable password level 15 Sets the enable mode password

enable secret Sets the encrypted enable secret password. Supersedes the enable password if set

encapsulation Sets the frame type used on an interface

encapsulation frame-relay Changes the encapsulation to Frame Relay on a serial link

encapsulation frame-relay ietf Sets the encapsulation type to the Internet Engineering Task Force (IETF); connects Cisco routers to off-brand routers

encapsulation hdlc Restores the default encapsulation of HDLC on a serial link

encapsulation isl 2 Sets ISL routing for VLAN

encapsulation ppp Changes the encapsulation on a serial link to PPP

erase startup Deletes the startup-config

erase startup-config Deletes the contents of NVRAM on a router

Esc+B Moves back one word

Esc+F Moves forward one word

exec-timeout Sets the timeout in seconds and minutes for the console connection

exit Disconnects a connection to a remote router via Telnet

frame-relay interface-dlci Configures the PVC address on a serial interface or subinterface

frame-relay lmi-type Configures the LMI type on a serial link

frame-relay map protocol address Creates a static mapping for use with a Frame Relay network

Host Specifies a single host address

hostname Sets the name of a router or a switch

int e0.10 Creates a subinterface

int f0/0.1 Creates a subinterface

interface Puts you in interface configuration mode; also used with show commands

interface e0/5 Configures Ethernet interface

interface ethernet 0/1 Configures interface e0/1

interface f0/26 Configures Fast Ethernet interface 26

interface fastethernet 0/0 Puts you in interface configuration mode for a Fast Ethernet port; also used with show commands

interface fastethernet 0/0.1 Creates a subinterface

interface fastethernet 0/26 Configures interface f0/26

interface s0.16 multipoint Creates a multipoint subinterface on a serial link that can be used with Frame Relay networks

interface s0.16 point-to-point Creates a point-to-point subinterface on a serial link that can be used with Frame Relay

interface serial 5 Puts you in configuration mode for interface serial 5 and can be used for show commands

ip access-group Applies an IP access list to an interface

ip address Sets an IP address on an interface or a switch

ip classless A global configuration command used to tell a router to forward packets to a default route when the destination network is not in the routing table

ip default-gateway Sets the default gateway of the switch

ip domain-lookup Turns on DNS lookup (which is on by default)

ip domain-name Appends a domain name to a DNS lookup

ip host Creates a host table on a router

ip name-server Sets the IP address of up to six DNS servers

IP route Creates static and default routes on a router

ipx access-group Applies an IPX access list to an interface

ipx input-sap-filter Applies an inbound IPX SAP filter to an interface

ipx network Assigns an IPX network number to an interface

ipx output-sap-filter Applies an outbound IPX SAP filter to an interface

ipx ping A Packet Internet Groper used to test IPX packet on an internetwork

ipx routing Turns on IPX routing

isdn spid1 Sets the number that identifies the first DS0 to the ISDN switch

isdn spid2 Sets the number that identifies the second DS0 to the ISDN switch

isdn switch-type Sets the type of ISDN switch that the router will communicate with; can be set at interface level or global configuration mode

K Used at the startup of the 1900 switch and puts the switch into CLI mode

line Puts you in configuration mode to change or set your user mode passwords

line aux Puts you in the auxiliary interface configuration mode

line console 0 Puts you in console configuration mode

line vty Puts you in VTY (Telnet) interface configuration mode

logging synchronous Stops console messages from overwriting your command-line input

logout Logs you out of your console session

mac-address-table permanent Makes a permanent MAC address entry in the filter database

mac-address-table restricted static Sets a restricted address in the MAC filter database to allow only the configured interfaces to communicate with the restricted address

media-type Sets the hardware media type on an interface

network Tells the routing protocol what network to advertise

no cdp enable Turns off CDP on an individual interface

no cdp run Turns off CDP completely on a router

no inverse-arp Turns off the dynamic IARP used with Frame Relay; static mappings must be configured

no ip domain-lookup Turns off DNS lookup

no ip host Removes a hostname from a host table

No IP route Removes a static or default route

no shutdown Turns on an interface

o/r 0x2142 Changes a 2501 to boot without using the contents of NVRAM

ping Tests IP connectivity to a remote device

port secure max-mac-count Allows only the configured amount of devices to attach and work on an interface

ppp authentication chap Tells PPP to use CHAP authentication

ppp authentication pap Tells PPP to use PAP authentication

router igrp as Turns on IP IGRP routing on a router

router rip Puts you in router rip configuration mode

secondary Adds a second IPX network on the same physical interface

Service password-encryption Encrypts the user mode and enable password

show access-list Shows all the access lists configured on the router

show access-list 110 Shows only access list 110

show cdp Displays the CDP timer and holdtime frequencies

show cdp entry * Same as show cdp neighbor detail, but does not work on a 1900 switch

show cdp interface Shows the individual interfaces enabled with CDP

show cdp neighbor Shows the directly connected neighbors and the details about them

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

show cdp traffic Shows the CDP packets sent and received on a device and any errors

Show controllers s 0 Shows the DTE or DCE status of an interface

show dialer Shows the number of times the dialer string has been reached, the idle-timeout values of each B channel, the length of call, and the name of the router to which the interface is connected

show flash Shows the files in flash memory

show frame-relay lmi Shows the LMI type on a serial interface

show frame-relay map Shows the static and dynamic Network layer-to-PVC mappings

show frame-relay pvc Shows the configured PVCs and DLCI numbers configured on a router

show history Shows you the last 10 commands entered by default

show hosts Shows the contents of the host table

show int f0/26 Shows the statistics of f0/26

show inter e0/1 Shows the statistics of interface ethernet 0/1

show interface s0 Shows the statistics of interface serial 0

show ip Shows the IP configuration of the switch

show ip access-list Shows only the IP access lists

show ip interface Shows which interfaces have IP access lists applied

show ip protocols Shows the routing protocols and timers associated with each routing protocol configured on a router

show ip route Displays the IP routing table

show ipx access-list Shows the IPX access lists configured on a router

show ipx interface Shows the RIP and SAP information being sent and received on an individual interface; also shows the IPX address of the interface

show ipx route Shows the IPX routing table

show ipx servers Shows the SAP table on a Cisco router

show ipx traffic Shows the RIP and SAP information sent and received on a Cisco router

show isdn active Shows the number called and whether a call is in progress

show isdn status Shows if your SPIDs are valid and if you are connected and communicating with the provider's switch

show mac-address-table Shows the filter table created dynamically by the switch

show protocols Shows the routed protocols and network addresses configured on each interface

show run Short for show running-config; shows the configuration currently running on the router

show sessions Shows your connections via Telnet to remote devices

show snmp Gives you the router's serial number as the "chassis" output

show start Short for show startup-config; shows the backup configuration stored in NVRAM

show terminal Shows you your configured history size

show trunk A Shows the trunking status of port 26

show trunk B Shows the trunking status of port 27

show version a show hardware command equivalent, which gives the IOS information of the switch, as well as the uptime and base Ethernet address

show vlan Shows all configured VLANs App.

show vlan-membership Shows all port VLAN assignments

show vtp Shows the VTP configuration of a switch

shutdown Puts an interface in administratively down mode

Tab Finishes typing a command for you

telnet Connects, views, and runs programs on a remote device

terminal history size Changes your history size from the default of 10 up to 256

trace Tests a connection to a remote device and shows the path it took through the internetwork to find the remote device

traffic-share balanced Tells the IGRP routing protocol to share links inversely proportional to the metrics

traffic-share min Tells the IGRP routing process to use routes that have only minimum costs

trunk auto Sets the port to auto trunking mode

trunk on Sets a port to permanent trunking mode

username name password password Creates usernames and passwords for authentication on a Cisco router

variance Controls the load balancing between the best metric and the worst acceptable metric

vlan 2 name Sales Creates a VLAN 2 named Sales

vlan-membership static 2 Assigns a static VLAN to a port

vtp client Sets the switch to be a VTP client

vtp domain Sets the domain name for the VTP configuration

vtp password Sets a password on the VTP domain

vtp pruning enable Makes the switch a pruning switch

vtp server Sets the switch to be a VTP server

Feedback received on this FAQ entry:
  • Great thanks

    2014-03-11 21:03:38

  • all good. thnx sir

    2014-02-17 08:21:03

  • really its very good document for descrption of all important commands thanks a lot

    2009-07-19 02:16:36

Expand got feedback?

by flw See Profile edited by aryoba See Profile
last modified: 2014-01-14 12:47:34