Basic Router & Switch IOS commands

 

Video Links:

Purpose	Command
To See running config file	Show   running-config   or sh  run
Displays configuration saved in NVRAM	Show  startup-config
To see IP info of interfaces	Show  ip interface brief
To see statistics of all interfaces	Show  interfaces
To see specific item from  running configuration	Show interface f0/0   [Only see the info of the specific interface f0/0 ] sh  run  | section  line  [Only see the info of all line sections] * If you want to see only DHCP section, nothing else sh  run  | section  dhcp show run | begin ip [If you want to see from that line where 'ip' word is present to last line] show run | exclude ip [If you want to see all lines but not to expect ip word related lines] show run | include ip [If you want to see all lines only included ip word related lines, not others]
Displays the system clock	Show  clock
Displays all users connected to the router	Show  users
To Disconnect specific remote users  or   To Disconnect specific  remote users	Clear   line   2 [2 means line number]   Clear line vty 0
To set idle time of remote session	Exec-timeout  1
Displays history of Cisco IOS	Show history
Displays info about Flash memory	Show  flash
Displays info about loaded Cisco IOS software	Show  version
Displays the ARP table of the router	Show  arp
Displays the IPv4 routing table of the router	Show  ip route
Displays the configured hostnames and their corresponding IP addresses of the router	Show  host
Displays status of configured Layer 3 protocols	Show  protocols
Display the CPU utilization for a Cisco device at five minute intervals.	Show  process  cpu
Display the total, used and available memory on a Cisco device.	Show  memory
Verify the operational status of fans, temperature and power supplies. In addition list the percentage of power supply utilization and what amount is available	show environment  all
Verify that CDP is enabled, update timer, hold timer and CDP version.	Show  cdp
To show remote users	Show  users
To show ssh information	Show  ssh
To change hostname(itbd) of a router	Hostname  itbd
How to assign a Local Name(remote) to an IP address(10.1.1.1)   [we can use the configured hostname for telnet or ping.like→ telnet  remote]	Ip  host  remote  10.1.1.1
Configure a MOTD Banner for Router	banner motd  #Welcome to IT-Bangladesh#
To enable DNS lookup	ip  name-server 192.168.100.10
To turn off the automatic name resolution	no ip domain-lookup
To get IP info automatically	Ip  add  dhcp
To resolve domain name	Ip  domain-lookup
To set DNS Server IP	Ip name-server  8.8.8.8
To set enable password(cisco)	Enable password cisco
To set secret password	Enable  secret cisco
To encrypt all password	Service password-encryption
To get IP info automatically into VPCS	Ip    dhcp
To set IP address(10.1.1.2/8) & Gateway(10.1.1.1) into VPCS	Ip  10.1.1.2/8   10.1.1.1
Delete all routes	Router#clear ip route *
To see all IP information of VPCS	Show  ip
To remove all the configuration commands you entered and initialize your Cisco device’s configuration	Router#erase startup-config Router#reload
To view the logs of the Cisco devices to which you have logged in via Telnet/SSH (Execute this command from remote machine)	# terminal monitor
To set Message of the day (MOTD) Banner	Banner  motd ~ MOTD Banner ~
To set Login Banner	Banner  login ~ Login Banner ~
To set exec Banner	Banner exec ~You are authorized person ~
To set timeout session for remote clients	Ip ssh time-out  5
To set authentication retries	Ip ssh authentication-retries  3