I have the following strange problem with the DNS lookups in our Windows domain (dns service runs on the domain controller):
from machine 'A':
- dns request for machines in the same network zone works
- dns request for adresses that are not "allowed" result in a timeout / no response
from machine 'B':
- both lookup requests work
Both machines use the same DNS server
This must mean that:
- the DNS server knows the correct addresses, and works correctly
- but: there is some other component (firewall?) in the network that intercepts some DNS requests, based on ckient machine AND request content, and decides to block this request by not returning a response.
This setup forces us to resort to using hostfiles for some connections, since the target machines are reachable.
What could be the reason to configure the network / firewall in such a 'broken' fashion, and what kind of firewall or other appliance has such 'functionallity'?