On Thu, 10 Mar 2005 11:30:51 CST, Paul Schmehl said: give details. I'll give you this much. We're having a > philosophical disagreement about the value of disallowing reverse dns for > hosts on our network. It's the ancient security by obscurity discussion. > > My concern is that we should not disable dns when (or if) it's required. > Obviously we would not disable it for the MX hosts, but I'm unclear what > (if anything) the RFC requirements are. Absent any requirements, there's > not cogent argument for *not* doing it, with the aforementioned exceptions. The security via obscurity is very slim - remember that if they're looking for the PTR entry, they *already* have the IP address.. One good reason to put the PTR out there is because it allows sanity-checking of your DNS - if you have 'foo.example.com A 10.10.100.1', then there should be a '1.100.10.10.in-addr.arpa PTR foo.example.com' to match. If you fumble-finger and get 'foo.example.com A 10.10.100.10', you can catch it because when you look up the PTR, you find '10.100.10.10.in-addr.arpa PTR bar.example.com'.
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