I installed several waves of Microsoft updates to our server last night (SBS 2003). All four of the VMs stopped responding on the network, but could talk to each other. They all used bridged networking and static IPs, running Ubuntu 7.10. A quick Google landed me here. After reading this thread and trying various solutions I found that nothing seemed to work.
Then I read devzero's post about the ARP issue (
http://communities.vmware.com/message/920916#920916). Running "vnetsniffer /e vmnet0" showed me the VMs sending out ARP requests but never getting anything back. So I was able to confirm his findings with my system. But what to do about it? Cycling the bridge device didn't help, nor did changing the MAC addresses of the VMs.
Just for a lark, I shut down all the VMs and (at random,) added a second bridged NIC to one of them. After firing it up - everything worked. I powered it off, removed the NIC, and tried again - still working. I then fired up all the VMs, and they are all working. Since I've been under pressure to get these back up I haven't tried a full reboot of the host server.
I hope this helps some other people out. I guess something in the VMNet arp table/cache got flushed or reset when the new NIC was installed - whatever it was I'm glad for a sudden flash of "whatthehelli'lltryit-ness"