I have a stack of new servers that I plan on using as domain controllers. I've installed 2008 on them and have begun the basic build. Today, I noticed that I couldn't browse to the hidden C$ share on one of them... so I tried to ping it... no go. I then went to the questionable server and was able to ping everything under the sun. I then went to the other servers in that stack and all but two responded to Pings. Those two that wouldn't respond to Pings could Ping outbound just fine. They are all plugged into the same switch.
Given that I could ping out, I decided to turn off Windows Firewall and give inbound another try. Still nothing. I changed network cables and the switch ports... still nothing. Pinging by name shows the correct IP address, but by name or not... it's still dead.
All servers in the stack have joined the new domain, fyi.