My dns server is a NetWare 5.1 server with SP 8. It holds master replicas for our tree and provides many of the dns and dhcp services. We suddenly find that it stops resolving dns for users. It does not start up again when I stop and start the service. I have to reboot the server. The server shows no errors on the console prompt and logs no errors in the dns/dhcp event log. It has no stuck replicas.

Eventually we realized that we got a new firewall installed the night before this started happening. The new one is a Cisco ASA 5520.

Does anyone have any ideas?