Overview of Router Commands:
We have read about routers, now is the time that we should learn few important commands of routers, These commands will make router certain functions. You will learn configuration of router, setting of privilege more commands, different protocols of routing, configuration of network and Cisco labs.Routers can be operated with basic and advance commands for different operations. Keeping all of these commands can never be easy therefore we are going to discuss those commands which are most commonly used to perform common functions for different operations. However before we commence on advance topic of router, it is better that we discuss about router related terminology which is commonly used.
Routing:
Transferring of data packets from one device to another with help of inter network.
In technical definition, routing is the process of communication between two or more physical networks and logical networks using router.
Router performs to most important but basic tasks, first it defines the path for data to be sent and then forward that data to defined path before we move on to configuration and commands of router.
Keyboard Shortcuts:
CTRL-N – For showing next command
CTRL-P – For showing command executed previously
SHIFT-CTRL-6 – Break
Configuring the Router :
These are few 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 – Automatic setup will start as if router is booting for the first time,
config t –It execute configuration commands from terminal
config mem – executes configuration commands stored in NVRAM; copies startup-config to running-config
config net -It retrieve configuration information 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 <put file filename here> – It 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 – It makes router boot from ROM
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 the list for most common commands for router.
reload – Command to restart the router
sh ver – It is 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 – Display date and time on router
sh history – Display the history of your previous commands
sh debug – display all debugging that is currently enabled
no debug all – turns off all debugging
sh users – Display users connected to router
sh protocols – Display configured protocols. banner motd # Your message # – Set/change banner
hostname <give router name> – use to configure the hostname of the router
clear counters – clear interface counters
Privileged Mode commands of a router
Following commands are used to work in the privileged mode of a router.
enable – get to privileged mode
disable – get to user mode
enable password < password here> – sets privileged mode password
enable secret < password here> – sets encrypted privileged mode password
Commands for Passwords settings on router
Most commonly used password related commands for router
enable secret < password here> – set encrypted password for privileged access
enable password < password here> – 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 <password here>
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 <put password here>
Set password for auxiliary (modem) access:
(config)#line aux 0
(config-line)#login
(config-line)#password <put password here>
Router Processes & Statistics :
Following are the commands which will display statistics and different processes of the router.
sh processes – Displays active processes running on router
sh process cpu – Display statistics for central processing unit (CPU)
sh mem – Display statistics for memory
sh flash – Description of the flash memory, show the size of files and the amount of free flash memory
sh buffers – Displays router buffer pools statistics; Displays size of the Small, Middle, Big, Very Big, Large and Huge Buffers
sh stacks – Displays reason for last reboot, monitors the stack use of processes and interrupts routines
Cisco Discovery Protocol uses layer 2 multicast over a SNAP-capable link to send data CDP Commands:
sh cdp neighbor – Display directly connected neighbors
sh cdp int – Display which interfaces are running CDP
sh cdp int eth 0/0 – Display CDP information for specific interface
sh cdp entry <CPD neighbor here> – Display 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 – Displays if CDP turned on
no cdp run – turns off CDP for entire router (global config)
no cdp enable – turns off CDP on specific interface
Other Commands:
sh ipx route – Display IPX routing table
sh ipx int e0 – Display ipx address on int
sh ipx servers – Display SAP table
sh ipx traffic – Show traffic statistics
debug ipx routing activity – debugs IPS RIP packets
debug ipx sap – debugs SAP packets
Routing Protocols
There are three routing protocols RIP, IGPR and OSPF, and below is of commands for 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 :
Below is list commands of access list of routers
.
sh ip int ser 0 – Display which IP access lists are applies to which int
sh ipx int ser 0 – Display which IPX access lists are applies to which int
sh appletalk int ser 0 – Display 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
Router is mainly used for networking using WAN, WAN is the network for which routers are the most obvious choice by network developers. Below is list of commands of methods of WAN connectivity.
PPP Configuration
Point to point protocol is one of the most used methods for the WAN connectivity; few of the commands of PPP mostly used are as follow.
encapsulation pppppp authentication <chap or pap here>
ppp chap hostname < router name here>
ppp pap sent-username <user name here>
sh int ser 0 – use to view encapsulation on the interface
Frame-Relay Configuration
One of the other methods for the WAN connectivity is the Frame Relay. Few some basic of commands for the WAN connectivity using Frame Relay method.
encapsulation frame-relay ietf – use IETF when setting up a frame-relay network between a Cisco router 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
Other Useful Commands
List of some of miscellaneous and useful commands which can be used for useful Operations.
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)
