Firewalls

other security precautions must be in place. One advantage of imple-

menting the firewall as a DNS server is that it can be configured to

hide the internal host information of a site. In other words, with the

firewall acting as a DNS server, internal hosts get an unrestricted

view of both internal and external DNS data. External hosts, on the

other hand, do not have access to information about internal host

machines. To the outside world, all connections to any host in the

internal network will appear to have originated from the firewall.

With the host information hidden from the outside, an attacker will

not know the host names and addresses of internal ...