Why aren't host names showing up with ssh

Greetings.

I have a bunch of GNU-Linux machines set up on a local network through a peripheral router. IP addresses are buttigned statically rather than by DHCP. The router has a built-in DNS server which I've used to buttign names to the computers on the Intranet:

10.0.0.2 router.example.com 10.0.0.3 foo.example.com 10.0.0.4 bar.example.com

So far so good. When I'm on foo, I can type "ping bar", and that works, so obviously the router is properly handling the host names.

I can also type "ssh bar" from foo to get a remote shell on bar. However, it annoys me that when I type "who", "finger", "last", or any other command that is supposed to list incoming connections, it lists only the IP address (10.0.0.3), not the host name (foo or foo.example.com):

Login: joe Name: Joe User Directory:home-joe Shell:bin-bash On since Tue Apr 11 20:56 (BST) on pts-5 from 10.0.0.3

joe pts-5 10.0.0.3 Tue Apr 11 20:56 still logged in

On every other system I've worked with, such commands show the host name instead of the IP address. Is there something I haven't properly configured here or is my router misbehaving?

Regards, Tristan

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