Unable to ping and login via short path

[Shoyru]

Hi Everyone
I have a problem here.
We have a server which is unable to recognise all other servers if we use the short form for it. Example:

1. ping tiger.cos
NO reply
2. ping tiger.cos.dbs.com
ping works!!

This problem only occurs today and it is giving me a headache - I have no idea what is wrong. Could someone advice me please? Much appreciated in advance! Thanks...:)

[Rajeev Shukla]

Hi,
It looks like a DNS issue.
Try couple of things
nslookup tiger.cos
nslookup tiger.cos.dbs.com

Have a look at /etc/nsswitch.conf
/etc/resolv.conf
Has someone changed something, if it was working before. If not pls post the entries of both the files.

cheers
Rajeev

[A. Clay Stephenson]

I would check the domain entry in /etc/resolv.conf. I would also check the /etc/hosts entry for this host. The fully qualified hostname for this host should be the first entry for this host with the short form as an alias. Man 4 resolver for more details.