DNS reverse lookup doesn't work from outside

[Jim Reid]

>>>>> "vijay" == vijay  <vijay at buydeal.com> writes:

    vijay> Hi Kevin/list users, I have Dedicated T1 line from SBC, I
    vijay> configured Bind 9 on Solaris box for our domain by name
    vijay> buydeal.com, dns-01.buydeal.com is the name-server which is
    vijay> bind to 68.249.200.20.  You can check this online it's not
    vijay> doing reverse lookup, but on the same
    vijay> system(dns-01.buydeal.com) it does reverse lookup.

Talk to your ISP. They have setup the reverse DNS entry for this IP
address (20.200.249.68.in-addr.arpa) as a CNAME which points at
20.0.200.249.68.in-addr.arpa. But there's no delegation for
0.200.249.68.in-addr.arpa. If you can find someone clueful at your
ISP, you should just tell them that reverse lookups don't work for
68.249.200.20 (and the rest of your /25??) and they will be able to
figure it out from there. They'll need to fix this, probably with some
co-ordination with you.

You could make your name servers serve this 0.200.249.68.in-addr.arpa
zone and populate it with PTR records for your hosts. Then they could
delegate the zone to your servers. For more details read RFC2317 or do
a google search for "classless reverse delegation". In fact I just did
this and found a reference to a document from your ISP:

     The Preferred Method for classless reverse delegation of SBC LAN
     IP blocks should be the first option applied for most customers
     to include reverse delegating ...  
     dedicated.sbcis.net/customer_support/reverse_delegation.html