LDAPWiki: CISCO Commands

The following commands are executed by pressing the appropriate key:

Question Mark: Gets help.
- Use at any prompt to see what commands can be executed there.
- Type in the beginning of a command, followed directly by a question mark (no space in between), to see the commands starting with those characters.
- Type in a command, then a space, then a question mark, to see options.
Q: When in user or privileged EXEC mode, logs you out of the router. When at the "---More---" prompt, returns you to the EXEC prompt.
Tab: Completes a partial command name entry.
Backspace: Erases the character to the left of the cursor.
Return: When at the "---More---" prompt, displays the next line.
Space Bar: When at the "---More---" prompt, displays the next screen.
Left Arrow: Moves the cursor one character to the left (same as Ctrl-B).
Right Arrow: Moves the cursor one character to the right (same as Ctrl-F).
Up Arrow: Recalls commands in the history buffer, beginning with the most recent command (same as Ctrl-P).
Down Arrow: Recalls more recent commands in the history buffer (same as Ctrl-N).

The following commands are executed by pressing the keys simultaneously:

Ctrl-A: Moves the cursor to the beginning of the line.
Ctrl-B: Moves the cursor back one character (same as Left Arrow).
Ctrl-C: When in any config mode, ends the config mode and returns you to privileged EXEC mode.
Ctrl-D: Deletes the character at the cursor.
Ctrl-E: Moves the cursor to the end of the command line.
Ctrl-F: Moves the cursor forward one character (same as Right Arrow).
Ctrl-I: Redisplays the system prompt and command line (same as Ctrl-L and Ctrl-R).
Ctrl-K: Deletes all characters from the cursor to the end of the command line.
Ctrl-L: Redisplays the system prompt and command line (same as Ctrl-I and Ctrl-R).
Ctrl-N: Recalls more recent commands in the history buffer (same as Down Arrow).
Ctrl-P: Recalls commands in the history buffer, beginning with the most recent command (same as Up Arrow).
Ctrl-R: Redisplays the system prompt and command line (same as Ctrl-I and Ctrl-L).
Ctrl-T: Transposes the character to the left of the cursor with the character located at the cursor.
Ctrl-U: Deletes all characters from the cursor back to the beginning of the command line (same as Ctrl-X).
Ctrl-V: Inserts a code to indicate to the system that the keystroke immediately following should be treated as a command entry, not as an editing key (same as Esc Q).
Ctrl-W: Deletes the word to the left of the cursor.
Ctrl-X: Deletes all characters from the cursor back to the beginning of the command line (same as Ctrl-U).
Ctrl-Y: Recalls the most recent entry in the delete buffer. The delete buffer contains the last ten items you have deleted or cut. Ctrl-Y can be used in conjunction with Esc Y.
Ctrl-Z: When in a config mode, ends the config mode and returns you to privileged EXEC mode. When in user or privileged EXEC mode, logs you out of the router.
Ctrl-Shift-6: All-purpose break sequence. Use to abort DNS lookups, traces, pings, etc.
Ctrl-Shift-6, followed by X: Suspends (but doesn't terminate) a telnet session. To see the open sessions, use "show sessions". To return to a suspended session, enter that session's number followed by the * Return key. To return to the most recently suspended session, hit the Return key at the EXEC mode prompt.

The following commands are executed by pressing and releasing the escape key, and then pressing the appropriate letter:#

Esc B: Moves the cursor back one word.
Esc C: Capitalizes the word from the cursor to the end of the word.
Esc D: Deletes from the cursor to the end of the word.
Esc F: Moves the cursor forward one word.
Esc L: Changes the word to lowercase from the cursor to the end of the word.
Esc Q: Inserts a code to indicate to the system that the keystroke immediately following should be treated as a command entry, not as an editing key (same as Ctrl-V).
Esc U: Capitalizes from the cursor to the end of the word.
Esc Y: Recalls the next buffer entry. The buffer contains the last ten items you have deleted. Press "Ctrl-Y" first to recall the most recent entry. Then do "Esc Y" up to nine times to recall the remaining entries in the buffer. If you bypass an entry, continue to press "Esc Y" to cycle back to it.

You'll also find the following commands to be useful (when specifying options, don't include the brackets):

conf t: When in privileged EXEC mode, puts you into global config mode.
copy run start: Saves the running config to NVRAM. This is an overwrite.
copy start run: Merges the startup config into the running config. This is NOT an overwrite.
debug option: Starts the specified debugging. Use "debug ?" to see the choices.
en (enable): When in user EXEC mode, gets you into privileged EXEC mode.
end: When in a config mode, takes you back to privileged EXEC mode.
ex (exit): When in user or privileged EXEC mode, logs you out of the router. When in global config mode, takes you to privileged EXEC mode. When in a specific config mode, takes you back to global config mode.
int type number: When in any config mode, takes you to interface config mode for the specified interface.
logg sync (logging synchronous): When in line config mode, turns on automatic redisplay of command lines interrupted by console messages.
no logging console: When in global config mode, shuts off informational messages ("logging console" turns them back on).
no ip domain-lookup: When in global config mode, shuts off DNS name resolution ("ip domain-lookup" turns it back on).
router protocol AS-number: When in global config mode, takes you to router config mode for the specified IP routing protocol.
term mon (terminal monitor): When in line config mode, sends debugging messages to the chosen terminal line.
un all (undebug all): When in privileged EXEC mode, shuts off all debugging.

Show Commands#

Commonly used "show" commands (when specifying options, don't include the brackets):

sh config: The obsolete, pre-10.3 version of "sh start".
sh cont type number: Layer-1 info for specified interface, including cable type, DTE/DCE, etc. Example: "sh cont e 3" (NOT "sh cont e3").
sh int type number: Layer-2 info for specified interfaces. Example: "sh int e0".
sh protocol int type number: Layer-3 info for the specified protocol and interface. Example: "sh ip int s2".
sh proto: Active Layer 3 protocols.
sh ip proto: Active IP routing protocols.
sh protocol route: Routing table for the specified protocol. Example: "sh ip route".
sh run (show running-config): Shows the running config. Obsoletes "write terminal".
sh start (show startup-config): Shows the startup config. Obsoletes "show config".
wr term: The obsolete, pre-10.3 version of "sh run".

Copy TFTP commands (used to backup and restore configs and IOS):#

copy flash tftp: Copies a file from flash to a TFTP server.
copy run tftp: Copies the running config to a TFTP server.
copy start tftp: Copies the startup config to a TFTP server.
copy tftp flash: Copies a file from a TFTP server to flash.
copy tftp run: Merges a file on the TFTP server into the running config.
copy tftp start: Replaces the startup config with a file from a TFTP server.

Hints for "copy" commands which involve a TFTP server ...#

Make sure that the TFTP server software is configured and running. Make sure that the router can see the TFTP server (PING it). Execute the appropriate "copy" command. Make sure that you READ THE QUESTIONS before you answer them!

Useful terms:#

Flash: Special type of RAM that does not lose its contents when power is removed. Used to store IOS.
IOS (Internetwork Operating System): Cisco's operating system. Stored in flash.
NVRAM (Non-Volatile RAM): RAM with a battery attached, used to store the startup config.
POST (Power-On Self-Test): Diagnostics performed at boot-up, tests the hardware.
RAM (Random-Access Memory): Stores frequently-changing data, such as ARP caches, routing tables, packets awaiting forwarding, etc.
ROM (Read-Only Memory): Chipset on system board where POST and boot loader (and, on some routers, an IOS subset) are stored.
running config (also known as "current" or "active" config): How the router is currently configured. Stored in RAM.
startup config (also known as "backup" config): How the router will be configured at the next restart. Stored in NVRAM.

Remember ...#

Show commands don't work from ANY config mode.
Config commands don't work from user or privileged EXEC mode.
Hot keys and command keywords are not case-sensitive, BUT PASSWORDS ARE!
Some (not all!) of these commands work on some (not all!) of the switches.

Basic Router Commands

To get into Privilege Mode from User

mode - enable

To exit out of Privilege mode disable

To exit the router - Exit or logoff

Previous Command - Up arrow or Ctrl-P

Next Command - Down arrow or Ctrl-N

Move forward one character - Right arrow or Ctrl-F

Move back one character - Left arrow or Ctrl-B

Break Key or Cancel - <ctrl>“c”

Auto Complete the command - <tab>

Setting Passwords

Set Password for Console Port line console 0

login

password password

Set Password for Telnet

line vty 0 4

login

password password

Set Password for Privilege (Enabled) mode

enable password password

Set Encrypted password for Privilege mode

enable password password

Router Configuration Commands

To go from Privilege mode to Global

Configuration mode

configure terminal

To copy the running-configuration to the

start-up configuration

copy run start

To copy the startup-config to the runningconfig

copy start run

To copy the startup-config to a TFTP

server

copy start tftp

To copy the running-config to a TFTP

server

copy run tftp

Save a backup of the IOS to a TFTP server

copy flash tftp

Upgrade the IOS from a TFTP server

copy tftp flash

Tell the router which IOS in flash to boot

from

boot system flash {filename}

Tell the Router which IOS to request from

a TFTP server (usually a fallback option)

boot system tftp {filename}

Viewing the Router’s Information

IOS Version info

show version

Current config stored in RAM

show running-config

Configuration stored in NVRAM

show startup-config

To see IOS info stored in flash

show flash

To see information on the interfaces

show interfaces

To see a summary of the interfaces

show ip int brief

To see processor utilization show processes cpu

Configuring an Interface

To access an interface “From Global config”

interface {type} {number}

example : interface Ethernet 0

To set Clock rate on a serial interface

Clock rate {kbps}

Example : clock rate 64000

Enable the interface

no shutdown

Disable the interface

shutdown

Assign an IP address to an Interface ip address {Ip address} {subnet mask}

Example: ip address 10.1.1.1 255.255.255.0

Configuring TCP/IP

To enable IP routing on a Router “From Global config”

ip routing

To disable IP routing on a Router

“From Global config”

no ip routing

Displays values about routing timers,

networks, and routing information.

show ip protocols

Displays contents of the routing table.

show ip route

Assign an [IP Address] to an Interface ip address {Ip address} {subnet mask}

Example: ip address 10.1.1.1 255.255.255.0

Manually setups up a host table mapping a

hostname to an ip address.

ip host name “ ip” “addresss”

Displays the host table show hosts

Configure RIP router rip

network “network address”

Configure IGRP Router rip

Network “network address”

Displays RIP updates [debug] ip rip

Displays IGRP transactions debug ip igrp transactions

Displays IGRP summary transactions Debug ip igrp events

Displays status and global parameters

associated with an interface

show ip interfaces

Allows remote management of a device telnet “ip address of host”

Uses ICMP to verify hardware connection

and logical address of the network layer

ping “network address”

To setup a static route ip route “network” “mask” “next hop address”

IPX configuration

Enable IPX on a router ipx routing

To enable load balancing ipx maximum-paths “number”

To assign a IPX network address to an

interface

ipx network “network number”

To set the encapsulation type on an

interface

encap novell-ether

encap sap

encap arpa

encap snap

To view the IPX routing table show ipx route

To view an IPX address on an interface show ipx interface

To view the sap table show ipx servers

To view IPX traffic statistics show ipx traffic

To view the IPX rip updates debug ipx routing activity

To view the SAP packets coming and

going

debug ipx sap

Cisco Discovery Protocol

See info on directly connected neighbors

Add “detail” to the end for more info

show cdp neighbors

To see what interfaces are runnning CDP

show cdp interface

To specify and particular neighbor and see

CDP information

show cdp entry “hostname”

To turn off CDP for the entire router no cdp run

To turn off CDP for an interface No cdp enable

To change how often the router sends CDP

updates

cdp timer “seconds”

To change how long the router will wait

before it’s removes a CDP neighber from

it’s table

cdp holdtime “seconds”

Access-Lists

IP Standard Access Lists 1-99

Set parameters for this access list

test statement

access-list access-list-number,

permit |deny, source, [source-mask]

Enable an interface to become part

of a group that uses the specified

access list.

protocol access-group access-listnumber,

in | out

IP Extended Access Lists 100-199

Set parameters for this access list

entry

access-list Access-list-number,

permit |deny, protocol, source,

source-mask,

destination, destination-mask,

[operator

operand], [established]

Enable an interface to become part

of a group that uses the specified

access list.

protocol access-group accesslist-

number, in | out

Assigns an alpha-numeric name

string to an access list

ip access-list standard |

extended name

Activates the access list on an

interface

ip access-group name | 1-199,

in | out

Can be used to verify whether

access lists are set

show ip interfaces

Displays the contents of all access

lists

show access-lists

IPX Standard Access Lists 800-899

Set parameters for this access list

entry

access-list Access-list-number,

permit | deny, source-network

[.source-node],

[source-node-mask], [destinationnetwork],

[.destination-node] [destinationnode-

mask]

Enable an interface to become part

of a group that uses the specified

access list.

ipx access-group access-listnumber,

in | out

IPX Extended Access Lists 900-999

Set parameters for this access list

entry

access-list Access-list-number,

permit |

deny, protocol, source-network

[[[.source-node]source-node-mask] |

[.source-node

source-network-mask.source-nodemask]],

[source-socket], [destinationnetwork],[[[.

destination-node] destination-node-

mask] | [destination-node

destination-network-

mask.destination-node-mask]],

[destination-socket], [log]

Enable an interface to become part

of a group that uses the specified

access list.

ipx access-group access-listnumber,

in | out

IPX SAP Filter Access Lists 1000-

1099

Creates an entry in a SAP filter

list

access-list Access-list-number,

permit |

deny, network [.node], [networkmask

node-mask], [service-type [servername]]

Activates the output SAP filter on

the interface

ipx output-sap-filter accesslist-

number

Activates the input SAP filter on

the interface

ipx input-sap-filter accesslist-

number

Displays information about the

config of the interface including

SAP filter numbers.

show ipx interface

WAN configuration

PPP Authentication

On each router defines the username

and password to

expect from the remote router

username name password secret

Configure the interface for ppp

encapsulation

encapsulation ppp

Configure ppp authentication type PPP authentication chap | chap pap

|pap chap | pap

Enables PAP on an interface

(disabled by default)

ppp pap sent-username

username password password

To use the same host name on

multiple routers

ppp chap hostname hostname

Use to authenticate to an unknown

host. This password is

not used when the router

authenticates a remote device.

ppp chap password secret

Displays authentication sequence as

it occurs

[debug] ppp [authentication]

Configuring Frame Relay

Specifies encapsulation type.

encapsulation frame-relay

[cisco | ietf]

Specifies LMI type used by the FR

switch. (default cisco)

frame-relay lmi-type ansi |

cisco | q933i

Inverse ARP is enabled by default.

If it has been disabled use this

command to enable it.

frame-relay inverse-arp

[protocol] [dlci]

Used to define the address to DLCI

table statically.

frame-relay map protocol protocoladdress

dlci [broadcast] [ietf | cisco ]

Displays the route maps (static or

dynamic)

show frame-relay map

Displays LMI information show frame-relay lmi

Selects a subinterface to configure interface serial

number.subinterface-number

multipoint | point-to-point

Defines the local DLCI number being

linked to the interface

frame-relay interface-dlci dlcimumber

Misc. Commands

Remove 10 minute interval router

waits for input

no exec-timeout or exec-timeout 0 0

Set clock clock set 20:26:00 04 July 2001

Change number of lines history will

record (max 256)

terminal history size “lines”

Sets token ring speed to 16 Mbps ring-speed 16

Enables early token release early-token release

Specifies a media independent

interface physical connection

media-type 10baseT

set the configuration register

(where to boot from) 0 for

ROM Monitor, 1 for ROM, 2 NVRAM.

config-register 0x2102

More Information#

There might be more information for this subject on one of the following:

Cheat Sheets