secondary server not working on most domains

Re: secondary server not working on most domains

From:

Date:

Time:

At 4:31 PM -0700 6/4/01, Global Homes Webmaster wrote:
>On 06/04/01 at 18:38, Robert Burr wrote:
>
> > On another note, I am running reverse DNS for all my servers and
> > workstations in my local area net, but how can I be sure by new ISP
> > has delegated them to my dns server?
>
>By querying the root servers for the reverse zone and following the NS
>records. Starting from quantumleap.net, which resolves to 64.243.104.200, the
>reverse zone for the Class C block is 104.243.64.in-addr.arpa. The
>c.root-servers.net server says that the parent zone (234.64.in-addr.arpa.) is
>delegated to savvis.net:
>
> 243.64.in-addr.arpa. 345600 NS ns1.savvis.net.
> 243.64.in-addr.arpa. 345600 NS ns2.savvis.net.
>
>ns1.savvis.net says that 104.243.64.in-addr.arpa. is delegated to the same
>servers:
>
> 104.243.64.in-addr.arpa. 3600 NS ns1.savvis.net.
> 104.243.64.in-addr.arpa. 3600 NS ns2.savvis.net.
> 104.243.64.in-addr.arpa. 3600 NS ns3.savvis.net.
>
>If you have a full Class C block (64.243.104.0 - 64.243.104.255), then we now
>know that the reverse zone is not delegated to you. If you don't have a full
>Class C block, then Savvis would have to do some flavor of classless
>delegation to give you control of the reverse zone for your subnet, and there
>would be one more zone to check. There are a number of choices for what the
>classless zone could be named, so without knowing its name we can't check the
>delegation. In any case, Savvis is unlikely to have delegated your reverse DNS
>to you unless you have specifically asked them to do so, whether it's for a
>full Class C or some smaller block.

Not quite true - we can take this further. I queried the savvis.net
servers for the normal PTR record name itself, and found this:

200.104.243.64.in-addr.arpa. NS dns.quantumleap.net.

So we see that the individual IP address has been delegated to
dns.quantumleap.net. Therefore, they expect you to have individual
zone files for each individual IP address.

Of course, you have a class C subnet reverse zone
(104.243.64.in-addr.arpa), which is not correct. You have two options
(pick one):

1. Create a bunch of "class D" reverse zones, one per IP address.

2. Ask Savvis to get a clue and use the classless subnet reverse zone
method, which would permit you to keep all your PTR records in one
zone. The name of the zone would be determined by Savvis.
____________________________________________________________________
Chris Buxton Men & Mice
cbuxton@menandmice.com We Make DNS Easy!

Sales:
888/4-DPOINT

Support:
858/452-3696