2013-12-26

Translating...domain server....wait...be-frustrated

One of the most annoying features of Cisco's IOS is the assuming that anything you type which is not a command is a hostname.  So...

Router#dev
Translating "dev"...domain server (255.255.255.255)
 (255.255.255.255)
Translating "dev"...domain server (255.255.255.255)
....

... and when you are configuring a router which either (a) does not have DNS, (b) is on a network that is down, or (c) is on the workbench and not actually connected to a network - you get to enjoy the long pause of a DNS timeout.

Argh!

The solution is simple:

Router#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#no ip domain-lookup
Router(config)#exit

The "no ip domain-lookup" disables this feature. Now at least it fails instantly:
Router#dev
Translating "dev"
Translating "dev"
% Bad IP address or host name
% Unknown command or computer name, or unable to find computer address
The downside is that the router will no longer perform DNS look-ups to translate host names to addresses.  That is bad for some specific use-cases [a VPN terminator is one possible example] - but generally that is not something that matters for a router.  Once a router is configured you can always turn domain-lookup back on.

Note to self: everytime you pull a router out of storage - do this first.

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