Cisco IOS little helper

A few commands to make life easier while configuring Cisco devices:

Synchronous logging

Normally the default logging will “interrupt” typing at the console. This can be prevented with synchronous logging.

Switch(config) #line vty 0 4
Switch(config-line) #logging synchronous

It must be configured on all “lines”, eg. Console, Telnet, SSH.

Exec timeout

By default, configuration sessions will be terminated after being idle for 5 minutes. The timeout can be customized by using the “exec-timeout” command:

Switch(config) #line vty 0 4
Switch(config-line) #exec-timeout MINUTES

As with synchronous logging, this setting has to be configured on all “lines”.

DNS resolution

For troubleshooting (eg. ping/traceroute) it can be very helpful to enable name resolution by configuring the correct DNS servers:

Switch(config) #ip name-server 8.8.8.8

Disable DNS lookups

By default any Cisco device will try to resolve unknown commands (eg. typos) to a DNS name. This can be prevented with:

Switch(config) #no ip domain-lookup