I have installed a 64bit Windows as a host on a Dell T610 server and then using Micosoft Hyper-V to provide a virtulised enviroment. I then have 2 guest systems, one being SBS2008, and the other windows server 2008 running an instance of SQL.
The servers have not been patched and have been running fine for the last 12 months.
On monday the SBS2008 server lost connectivity and the PCs were not able to ping it, however the SQL box which is running on the same Hyper V Host was able to be pinged.
After a reboot the systems seamed to work fine, but after 2 days the same problem happened again where the SBS2008 lost network connectivity, and the SQL server was able to be pinged from the client PCs.
The event log seams to be pretty clean with no errors.