DNS - Non-functional translation of PTR records on BIND server

Discussion in 'Server Operation' started by Jan Brodecky, Mar 10, 2023.

  1. Jan Brodecky

    Jan Brodecky New Member

    All of a sudden the resolution of PTR records on the authoritative DNS server stopped working.
    Translations of other record types (A, MX, TXT, ..) work.

    The server is running Debian 10.
    BIND version: BIND 9.11.5-P4-5.1+deb10u3-Debian (Extended Support Version)

    I tested the scenario from several networks.
    I also tried resolving records as localhost.

    Some zones are not loaded with .err on end of the file name. Could there be a connection?
    These zones were there even before the PTR record translation problem occurred.

    But what I'm concerned about is correctly loaded zones.

    I'll give you an example:

    Zone is loaded OK - checked with named-checkzone

    Zone configuration on named.conf.local:
    zone "3.2.1.in-addr.arpa" {
    type master;
    file "/etc/bind/pri.3.2.1.in-addr.arpa";

    zone file:
    $TTL 3600
    @ IN SOA server.domain.cz. support.domain.cz (
    2023031010 ; serial, todays date + todays serial #
    16384 ; refresh, seconds
    2048 ; retry, seconds
    1048577 ; expire, seconds
    2560 ) ; minimum, seconds

    @ 86400 NS server.domain.cz.
    3.2.1.in-addr.arpa 3600 NS server.domain.cz.
    3.2.1.in-addr.arpa 3600 NS server2.domain.cz. 3600 PTR gw-01-79.domain.cz.

    I set myself (localhost) as DNS server
    nslookup search:
    set type=PTR

    nslookup output:
    server can't find NXDOMAIN

    In some cases (with records in other reverse zones), the server responds: server can't find SERVFAIL
    I haven't found a reason why the answers differ.

    Could you help me solve the problem please?

    Best regards
    Jan Brodecky
  2. Taleman

    Taleman Well-Known Member HowtoForge Supporter

    Yes. Fix the errors first. I would use host command when testing the name server.
    Please post the listings in CODE tags.
    Are you sure the NS entries in zone file are correct? The syntax you used I have not seen. Perhaps the DNS and Bind Book by Albitz and Liu helps here.
  3. SamTzu

    SamTzu Active Member

    PTR's are in the hands of your ISP (just like your IP's).
    I would ask if they have done any changes in their DNS/PTR management.
    I have run in to same problem with our (email servers) PTR records being changed on the fly away from our control.
    It's basically only issue when dealing with email servers and even with them it's usually no problem.
    Last edited: Apr 4, 2023
  4. SamTzu

    SamTzu Active Member

    I would use dig to find the answer.
    [email protected] -x
    or something like:
    [email protected] www.server.com

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