Suggested prerequisite reading
»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
0.0.0.0 255.255.255.255 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 0.0.0.0 255.255.255.255 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 informa-tion 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 e0/1
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 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
»Cisco Forum FAQ »The most straight-forward way to configure Cisco router: Introduction to CLI
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
0.0.0.0 255.255.255.255 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 0.0.0.0 255.255.255.255 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 informa-tion 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 e0/1
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 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
