Progress but not a complete fix. It
looks like Windows 7 (excluding the VPN) removes the DNS suffix from it's TCP NetBios name when it's assigned an IP from any other DHCP server (except works). So connecting to a 'home' wifi; allocates it's IP perfectly; and sets the DNS suffix to null.
Right that means that when the VPN is connected; the network adapter is set to have a fixed DNS suffix...
the dns suffic is "domain.local". (it works for Win XP, why should Win 7 be any different).
So... if i specify a set of ping commands locally (on the works LAN).
PING MAIL > successfully resolves mailservername.domain.local as the FQDN... and success,
on the VPN...
PING MAIL > suggessfully resolves (after a bit of a delay)... mailservername.domain.local as the FQDN... and again success.
PING MAIL.DOMAIN.LOCAL > response from mailservername.domain.local... perfect!
so DNS lookups take time and do work...unless you put the DNS suffix in... logical
Right... the penultimate problem still remains though...
The domain controllers share a common name (the domain name = "domain.local").
PING DOMAIN.LOCAL > resolves the FQDN as DOMAIN.LOCAL > response from the primary DC - success.
on the VPN:
PING DOMAIN.LOCAL > no FQDN resolved... DNS times out... no response...
Windows 7 cannot locate the FQDN for DOMAIN.LOCAL; but only through a VPN interface... looks like it only checks the Primary Network Adapter's DNS servers... because they are definately set.
god this is getting complicated...