Redirector times-out

Hello,

I am experiencing the following problem on my NT LAN:

1. For no apparent reason, the BDC, servers and all PCs loose connection with the PDC and the whole network.

2. The PDC however has no problem accessing the BDC, servers and PCs.

3. The event viewers record the following Redirector error ID 3013: ” The redirector has timed out a request to ACL1″.

4. The PDC replies to a ping from anywhere on the LAN.

4. My only solution is to reboot the PDC.

Any help will be greatly appreciated.
Nicole