When working with the Cisco ISO it’s normal to receive some warnings and messages and they are vital for knowledge of the system but some tend to interrupt while working on a router. If you agree with the later one then disabling some of the unnecessary one’s is not that hard.
Router#line con 0
Router#line vty 0 4
In privileged mode Cisco routers attempt to resolve DNS hostname to IP addresses, this can frustrating when entering a wrong command creating a 30 to 40 second delay, the solution is to disable DNS look up.
Router#no ip domain-lookup
The result from now on will be “% Unknown command or computer name, or unable to find computer address“.
There is no need to erase the whole configuration if you need to wipe the interfaces, just erase the configuration on the interface instead.
Router(config)#default interface fastethernet0/0