CMS Database Connectivity

I am getting an intermitten problem where the CMS is not able to connect to the CMS Database (SQL Server) and then services shut down. This seems to happen over the weekends more so than the week days. The Windows Event logs indicate "CMS is unstable and will shut down immediately. Reason: Database access error. Reason [Microsoft][ODBC SQL Server Driver]Communication link failure."

I can't find any resolution for this other than dedicating communication on one NIC. We only have one NIC on the server. Any ideas?