Cannot ping computername but can if using FQDN

I have two domains (DOMAINA and DOMAINB). All computers in the domains can
ping each other using only the computer name.

I have a newly installed Windows 2003 computer that can ping computers in
its own domain using the computer name. However it cannot ping computers in
the other domain using only the computer name. It can ping computers in the
other domain using the fully qualified domain name.

As a workaround I can add the other domain to the list of DNS suffixes.

Why is this new computer unable to ping computers in the other domain using
only their computer name?

Solved this by disabling the Internet connection firewall. However, why does
the firewall cause this strange behaviour?

"Joseph Tervit" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I have two domains (DOMAINA and DOMAINB). All computers in the domains can
> ping each other using only the computer name.
>
> I have a newly installed Windows 2003 computer that can ping computers in
> its own domain using the computer name. However it cannot ping computers
in
> the other domain using only the computer name. It can ping computers in
the
> other domain using the fully qualified domain name.
>
> As a workaround I can add the other domain to the list of DNS suffixes.
>
> Why is this new computer unable to ping computers in the other domain
using
> only their computer name?
>
>