kinit: Cannot contact any KDC for requested realm while getting initial credentials

[Celia Clark]

Hi,

I am having problems with using kinit, with keytab and username/password.

When issuing the kinit command I get the following error:
kinit: Cannot contact any KDC for requested realm while getting initial
credentials
There is a firewall between the webservers where I issue the command from
and the domain controller.
The webservers are able to connect to the domain controller on port 88 over
UDP.

The webservers are able to resolve themselves and the domain controller,
both forward and reverse lookup.

Do any of you guys out there have an idea of what is going wrong?

Many thanks,

Celia