finding out more about reverse DNS and fixing it?

[Barry Margolin]

In article <caqbhg$bbr$1 at sf1.isc.org>, deja at celticbear.com (LRW) wrote:

> Can someone point me to something that explains what a no reverse DNS
> error indicates and how to take care of it?

Reverse DNS is used to translate IP addresses back to names, by using 
the IN-ADDR.ARPA DNS hierarchy.  To get the name associated with address 
1.2.3.4, you look up the PTR record of 4.3.2.1.in-addr.arpa.  Also, this 
will often be followed by a lookup of the name that resulted, to verify 
that it resolves to the original address, as a way of preventing being 
fooled by faked reverse DNS.

If you tell us the address of your mail server, we can check to see if 
there's any problem with its reverse DNS.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***