bind9 reverse zone dns config error - CNAME

Question

i am trying to set up a reverse zone for my bind dns server, under the subnet 192.168.0.65/29 my zone datafile looks like this:

   @       IN      SOA     server.example.com.   server.example.com.   (
                            2014101300 ; serial
                            1000       ; refresh
                            180        ; retry
                            180        ; expire
                            10         ; minimum
                            )

    65      IN      CNAME   65.64/29
    66      IN      CNAME   66.64/29
    67      IN      CNAME   67.64/29
    68      IN      CNAME   68.64/29

    66      IN      NS      server.example.com.

    65      IN      PTR     router.example.com.
    66      IN      PTR     server.example.com.
    67      IN      PTR     client-1.example.com.
    68      IN      PTR     client-2.example.com.

When i try to load this file it fails and displays the following error: "CNAME and other data". Any ideas to what might have gone wrong??

Answer 1

The CNAME records should be in your 0.168.192.IN-ADDR.ARPA. zone. It should also have glue records for the 64/27.23.168.192.IN-ADDR.ARPA. zone to which you are delegating.

65        IN  CNAME   65.64/29.0.168.192.IN-ADDR.ARPA. ;qualified
66        IN  CNAME   66.64/29 ;unqualified name
67        IN  CNAME   67.64/29 

The zone for 64/27.23.168.192.IN-ADDR.ARPA. should contain the rest of the records. If you are doing this on the same DNS server, you can omit the glue and NS records.

See How to Delegate Reverse Subnet Maps records for documentation and examples. RFC 2317, Classless IN-ADDR.ARPA delegation, has already been linked to.

Answer 2

The right hand side of a CNAME record should be a canonical name not something that looks like a CIDR address. See for instance RFC 2181 for clarification.

A more logical zone file would be one without all the CNAME RR records you have there.

Answer 3

Your Zonefile lists these entries for 66:

66      IN      CNAME   66.64/29
66      IN      NS      server.example.com.
66      IN      PTR     server.example.com.

So you do not only have a CNAME-record, but an NS and PTR as well, whis is explicitly forbidden. A CNAME "redirects" all queries (MX, A,...), so you may not override these by specifying additional resource records.

Apart from this, your zone file looks a little awkward to me; after the SOA-Record, I'd only expect this kind of entries:

@       IN      NS      server.example.com.

65      IN      PTR     router.example.com.
66      IN      PTR     server.example.com.
67      IN      PTR     client-1.example.com.
68      IN      PTR     client-2.example.com.

By the way, your CNAME's right hand side seems weird to me, "65.64/29.0.168.192.in-addr.arpa." will most probably not be resolvable (slashes not being allowed AFAIK), but I'm pretty sure, your setup won't need these CNAMEs.