We have added Win2008 R2 AD/DC/GC to our Domain and transferred the roles from our 2003 box to the 2008 box.
Since then we have lost machines that reside on site 1 and site 2 in the network neighbour hood and also in dameware.
We have also added DHCP, DNS roles on the 2008 servers and added these new boxes to all the servers with staic ip's.
We also attempted a change of firewall rules (managed by isp) which seems to be too coincidental.
So, any ideas what may be stopping viewing these machines???