Small Business Server randomly crashes

This morning i got a call from a client that she couldn't print or open outlook. Apparently, the pst file was sitting on the server. So, I logmein into her computer and pinged the router. That was okay. Then ,I pinged the server and it was off line.
To make a long story short, the server was offline. But, why was it offline? There were some unexpected shutdowns in the pass also. So, I checked the event logs and found some DNS /DHCP related issues. I cleared those and am now ready for peace and quiet from this client.