Date: Wed, 21 Apr 1999 10:13:33 -0600 From: Scott Brown <skb@asgard.slcc.edu> To: freebsd-questions@freebsd.org Subject: DNS through a firewall Message-ID: <371DF92D.1C74@asgard.slcc.edu>
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I've set up a 2.2.5 machine for firewall duty between my LAN and the world, using plain old kernel filtering (ipfw). I'm using the approach of denying everything that isn't explicitly allowed. Everything is great, it all works just fine. However, I'd like to know more about how DNS works. Since my firewall is also a secondary DNS for our domain, I included in my ruleset the three DNS rules from the "simple" rc.firewall section, though I had to modify the 2nd and 3rd rules (by replacing "${oip}" with "any") before my workstations could do name lookups. I'm satisfied for the moment with this setup -- my firewall is less about securing my machines than about preventing my users from abusing their network access -- but I'd really like to know more about the comings and goings of packets during DNS queries, and how named communicates with its primary. I've asked my supervisor to buy the ORA grasshopper and doorway books for me, but any tips in the meantime would be appreciated. Thanks, -Scott To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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