Reverse dns

[Paul Schmehl <pauls () utdallas edu>]

Is there an RFC *requirement* for reverse dns?

I've been looking through the RFCs and I can't find it.  Some folks think 
reverse dns should be completely disabled.  I know for sure that this will 
break email, because many mail servers won't talk to a server that doesn't 
reverse.  Tcpdump also doesn't like hosts that won't reverse.

What I'm looking for is a standard (RFC) that states that enabling reverse 
lookups is *required* or reverse lookups are *optional*.  If they're 
optional, then reverse could be disabled for most hosts.

I'm also looking for a list of things that *break* when you disable reverse 
(e.g. mail).

RULES FOR RESPONDING:
1) "Reverse is a good thing" is not an answer.  Neither is "Reverse is a 
bad thing".
2) Opinions are not useful -  stick to facts only - chapter and verse 
please.
3) All replies to the list please - others will find this useful as well.

Paul Schmehl (pauls () utdallas edu)
Adjunct Information Security Officer
The University of Texas at Dallas
AVIEN Founding Member
http://www.utdallas.edu
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