Forefront TMG 2010sp1 - creating an alternate external proxy forward for IT Admin use

[sacrej]

Morning,

 

just a quick query, and something thats stumped me for a while.

 

prior to the summer we were using ISA 2004 and on client machines we were able to type in unfiltered.proxy.****.***.sch.uk in our browser settings and it allow us unblocked access to the web - handy for when we need to download installers etc, or if we have to investigate a website that a student has accessed via proxy sites - the problem is with the new FFTMG server, we can no longer do this - if we try it on the actual server it works - i'm guessing as it has the external DNS etc. it can see the addresses (ping etc) but from the clients we cannot ping, nor can we ping external DNS. on closer inspection of our internal DNS, we can see in the forwarders tab that the two external DNS's are there, but under server FQDN, it states 'unable to resolve' - i'm 90% sure that this is the issue, but I dont know how to solve it....does anyone have any ideas?