NT4 servers – lose connections with RPC errors – endpoint problems.
A – Are you patched all the way to SP6a?
B – Did you do the RPC patches/rollup?
C – Which anti-virus are you running and is it up to date?
D – Are you hosting the DNS server or is it elsewhere?
– If it is hosted elsewhere, then the patches to that
– server and DNS itself no longer accept updates from
– you old system(s).
Last is this an internal network and do you control the routers? If not then check with Network they may have turned on the Filters which block RPC to stop viruses or worms.