I'm working in setting up DNS for our block of IPs. I've got forward
resolution working correctly, but the reverse is giving me problems.
This is what I know:
I have a block of IPs that I need to setup reverse lookups for. My
ISP uses RFC 2317 addresses (yes, I've read
http://homepages.tesco.net/~J.deBoynePollard/FGA/avoid-rfc-2317-delegation.html),
but AT&T is not exactly known for its flexibility and won't change
their delegated addresses. Here is what I know:
$ dnsq ptr 0.41.190.12.in-addr.arpa. a.root-server.net
12 0.41.190.12.in-addr.arpa:
142 bytes, 1+0+4+0 records, response, noerror
query: 12 0.41.190.12.in-addr.arpa
authority: 12.in-addr.arpa 86400 NS cbru.br.ns.els-gms.att.net
$ dnsq ptr 0.41.190.12.in-addr.arpa cbru.br.ns.els-gms.att.net
12 0.41.190.12.in-addr.arpa:
132 bytes, 1+1+2+0 records, response, noerror
query: 12 0.41.190.12.in-addr.arpa
answer: 0.41.190.12.in-addr.arpa 172800 CNAME 0.0\05728.41.190.12.in-addr.arpa
authority: 0\05728.41.190.12.in-addr.arpa 172800 NS ns1.pairnic.com
authority: 0\05728.41.190.12.in-addr.arpa 172800 NS ns2.pairnic.com
$ dnsq ptr 4.41.190.12.in-addr.arpa cbru.br.ns.els-gms.att.net
12 4.41.190.12.in-addr.arpa:
132 bytes, 1+1+2+0 records, response, noerror
query: 12 4.41.190.12.in-addr.arpa
answer: 4.41.190.12.in-addr.arpa 172800 CNAME 4.0\05728.41.190.12.in-addr.arpa
authority: 0\05728.41.190.12.in-addr.arpa 172800 NS ns1.pairnic.com
authority: 0\05728.41.190.12.in-addr.arpa 172800 NS ns2.pairnic.com
(I know that the nameservers point elsewhere right now; I'm just
setting this up and testing it before I go live with this.)
Here is where the problem starts. AT&T is actually going to delete
the block 0.0/28.41.190.12.in-addr.arpa to me. I don't think that '/'
is a valid character in DNS, but it is what it is. If I do the same
query above with dig, I can see this:
$ dig @cbru.br.ns.els-gms.att.net 4.41.190.12.in-addr.arpa.
...
;; ANSWER SECTION:
4.41.190.12.in-addr.arpa. 172800 IN CNAME 4.0/28.41.190.12.in-addr.arpa.
So for testing I've added the following to my data file:
##
## Reverse DNS
##
.0.0/28.41.190.12.in-addr.arpa:12.190.41.6:ns1.a3dauto.com:259200
^4.0/28.41.190.12.in-addr.arpa:mail.a3dauto.com:259200
But the problem is that when I query the server:
$ dnsq a 4.0/28.41.190.12.in-addr.arpa. 12.190.41.6
I can see the request in the logs:
0cbe2905:dc2f:afed - 0001 4.0\05728.41.190.12.in-addr.arpa
but there is no response. Forward lookups work fine, so I know the
service is running, etc.
So my question is what am I missing? I've tried various combinations
of escaping slashes, using '/' vs. '\057', etc. to no avail. What
would be the correct manner of handling this bizarre delegation?
Thanks.
|