Facing very high traffic from DNS Server to Firewall ?

Did you Observe high traffic from Specific DNS Server to Firewall which may cause hanging of Firewall ?

Do below.

1. Enable DNS Debugging logs from DNS Server properties (dnsmgmt.msc)

2. Configure detailed logs for few hours & observe in the logs

3. Check , what kind of query & which is the destination.

4. Verify all queries are getting forwarded to root hints ?

5. Else check at client level & DNS Server level for Virus ,

6. If all directing to Roothints - do below steps to block same.

7. Disable Recursion ( will disable Forwarders Also ) or Enable standard forwarding to another DNS Server.