Reverse lookups not working when Internet connection failed.

[David Carvalho]

Thanks again.

>So when your system(s) try to do a reverse DNS (PTR) lookup for 193.136.66.1, it will actually do a PTR lookup for 1.66.136.193.in-addr.arpa. and fail because you don't have a copy of the >66.136.193.in-addr.arpa. zone file locally.

Probably. Am I supposed to, I have just 2 segments in this network (and 2 others on another work) ?


>At least my understanding is that you have a copy of your forward zone, and your 0-28.66.136.193.in-addr.arpa. zone.  But you don't have a copy of, nor access to, the intermediate >66.136.193.in-addr.arpa. zone that references the 0-28.66.136.193.in-addr.arpa. zone.

Yes! But I never heard of intermediate zone before. As far as I know, my top domain forwards all "di.ubi.pt" requests to me and that works.

Regards
David


-----Original Message-----
From: bind-users <bind-users-bounces at lists.isc.org> On Behalf Of Grant Taylor via bind-users
Sent: 04 November 2022 17:07
To: bind-users at lists.isc.org
Subject: Re: Reverse lookups not working when Internet connection failed.

On 11/4/22 10:54 AM, David Carvalho via bind-users wrote:
> Thanks for the replies.

You're welcome.

> My reverse zone in named.conf. My secondary dns gets it automatically 
> daily, along with the "di.ubi.pt.".

ACK

> zone "0-28.66.136.193.in-addr.arpa." IN {
>          allow-query { any; };
>          type master;
>          file "rev0.hosts";
> };

That confirms that the origin is in fact "0-28.66.136.193.in-addr.arpa." 
  (Save for any typo that I may have introduced.)

> I'll have to study more about some things you guys wrote. This is 
> getting complicated 😉

So when your system(s) try to do a reverse DNS (PTR) lookup for 193.136.66.1, it will actually do a PTR lookup for 1.66.136.193.in-addr.arpa. and fail because you don't have a copy of the 66.136.193.in-addr.arpa. zone file locally.

At least my understanding is that you have a copy of your forward zone, and your 0-28.66.136.193.in-addr.arpa. zone.  But you don't have a copy of, nor access to, the intermediate 66.136.193.in-addr.arpa. zone that references the 0-28.66.136.193.in-addr.arpa. zone.

Does that help?

Please feel free to ask additional questions.



--
Grant. . . .
unix || die