How to setup Reverse DNS

[Barry Margolin]

In article <7k62mo$sd7$1 at nnrp1.deja.com>,  <myinternetnews at my-deja.com> wrote:
>My ISP assigned me an ip of 209.249.221.50/240.

That's not valid CIDR notation.  Did you mean 209.249.221.50/28,
i.e. having a subnet mask of 255.255.255.240?

>I have successfully setup everything on my DNS except it failed when I
>try to access some site that need reserve dns respond.
>Can someone tell me how to setup reverse DNS? or tell me where do I
>need to change.
>I have the /etc/named.conf and /var/named configured.

Your ISP needs to delegate the reverse DNS to you, using the technique
described in RFC 2317.

It looks like they've currently configured their own reverse DNS for this
address block.  All the 209.249.221.x addresses have PTR records pointing
to 209.249.221.x.fastpoint.net, but they haven't installed the
corresponding forward entries into the fastpoint.net domain.  Sites that
require reverse DNS generally check that the corresponding forward DNS
match up (since you could put anything you want in your reverse DNS), and
this is why things are failing.

-- 
Barry Margolin, barmar at bbnplanet.com
GTE Internetworking, Powered by BBN, Burlington, MA
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