In this tutorial I’ll discuss about how to remove or change configuration on cisco router/switch. when we have configured on router/switch but it’s wrong configuration or need to remove the configuration how to do that ? and when we need to change configuration how to do that ?
When we need to remove configuration on router/switch cisco we just only need to reconfigure it with added no in front of script.
Let say you already configured on router. check running configuration on your router.
MyRouter#show running-config Building configuration... Current configuration : 830 bytes ! version 16.6.4 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname MyRouter ! enable secret 5 $1$mERr$3HhIgMGBA/9qNmgzccuxv0 enable password 12345 ! ip cef no ipv6 cef ! spanning-tree mode pvst ! interface Loopback1 ip address 192.168.100.1 255.255.255.0 ! interface GigabitEthernet0/0/0 ip address 192.168.1.1 255.255.255.0 duplex auto speed auto ! interface GigabitEthernet0/0/1 no ip address duplex auto speed auto shutdown ! interface GigabitEthernet0/0/2 no ip address duplex auto speed auto shutdown ! interface Vlan1 no ip address shutdown ! ip classless ! ip flow-export version 9 ! banner motd ^CThis Is Router Core^C ! line con 0 ! line aux 0 ! line vty 0 4 login ! end MyRouter#
For example if you need to remove enable password and ip address on Loopback1 :
MyRouter(config)#no enable password
Show running config again :
MyRouter#show run Building configuration... Current configuration : 808 bytes ! version 16.6.4 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname MyRouter ! enable secret 5 $1$mERr$3HhIgMGBA/9qNmgzccuxv0 ! !
Enable password already removed.
Remove ip address from Loopback1 :
MyRouter(config)#int lo1 MyRouter(config-if)#no ip add 192.168.100.1 255.255.255.0 MyRouter(config-if)#exit
Show Running config again :
MyRouter#show run Building configuration... Current configuration : 783 bytes ! version 16.6.4 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname MyRouter ! enable secret 5 $1$mERr$3HhIgMGBA/9qNmgzccuxv0 ! ip cef no ipv6 cef ! spanning-tree mode pvst ! interface Loopback1 no ip address ! interface GigabitEthernet0/0/0 ip address 192.168.1.1 255.255.255.0 duplex auto speed auto !
IP Address from interface loopback1 already removed.
Now How to change the configuration ? for example we need to change ip address configuration on Interface Gigabit0/0/0 from 192.168.1.1 255.255.255.0 to 192.168.100.1 255.255.255.0
For change the configuration, just configure again in that interface.
MyRouter(config)#int g0/0/0 MyRouter(config-if)#ip add 192.168.100.1 255.255.255.0 MyRouter(config-if)#exit
Show Running-config on router :
MyRouter#show running-config Building configuration... Current configuration : 785 bytes ! version 16.6.4 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname MyRouter ! enable secret 5 $1$mERr$3HhIgMGBA/9qNmgzccuxv0 ! ip cef no ipv6 cef ! spanning-tree mode pvst ! interface Loopback1 no ip address ! interface GigabitEthernet0/0/0 ip address 192.168.100.1 255.255.255.0 duplex auto speed auto ! interface GigabitEthernet0/0/1 no ip address duplex auto
IP Address on Gigabit0/0/0 already change.