1. affected workstation are Optiplex 380 running Win 7 pro sp1 with broadcom NICs.
2. Internal users use a internal webserver for customer invoicing application. Users lose connectivity to this internal web server, all other networking works, network shares, internet, etc. If I try to ping the webserver IP I get no reply. XP machines are not affected. Not a DHCP issue as there are plenty of IPs.
3. I have tried different internal NICs (3com) but still had issue. I have upgraded BIOS, nic drivers. etc.
4. I rebuilt one of the machines using Windows XP pro sp3 and have had no issue with that workstation.
the problem started a few months or so ago. I have not been able to determine the source. I tried running wireshark but nothing stuck out. I have changed the session settings on the IIS server from 15 minutes to 6 hours but did not make a difference.
5. Today when client lost connectivity to the server I tried pinging from the server back to the client and the connection was restored. This issue really has me confused as I cannot find anything in the logs that sticks out.