I have the following problem with an SBS2011 installation, running as a virtual machine on a VMware ESXi:
The NIC card is an Intel 82574L with 2 ports integrated in a Supermicro motherboard virtualized as E1000 in an ESXi 5.1 environment.
Every once in a while (it can happen twice a day or never happen for two weeks) the NIC card becomes completely unresponsive. On the 'Local area connection status' the 'Media State' read 'Enable' but it blinks.
Disabling and Re-enabling the card does not help, and I can only restart the server to solve the problem.
VMware, Firewall (pfSense with snort installed) and the server logs show absolutely nothing network related.
I am sure that the on the physical side the NIC is still working because pfSense is on the same host and keeps routing packets in the internal and external network.
I'd be happy just to have even just a suggestion on where to search to solve this. I have two other identical configuration in the other branch offices (only different NIC card), that have no problem.
Thanks in advance,