DNS Reverse lookup

[Mark Seida]

I am setting up dns in a closed network with subdomains there is no contact with any root servers. I modified the db.cache file to make it the root server. I am running bind 4.9.7 on hpux 11.00. The root server is .com and then I have mn..com and be..com are the subdomains. I can do forward name resolution but not reverse. Any sugestions would be appriated.

[Vincenzo Restuccia]

See http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/J2776-90008/J2776-90008_top.html&con=/hpux/onlinedocs/J2776-90008/00/00/20-con.html&toc=/hpux/onlinedocs/J2776-90008/00/00/20-toc.html&searchterms=dns&queryid=20010606-093209

[Kevin Wright]

are your PTR records set up? probably not. You should really be using a newer bind, but regardless, do you have both forward and reverse zone files defined in named.conf..boot for you.

[Mark Seida]

All servers are running HPUX 11.00 and we are not trying to create load balancing. I am just trying to get reverse name resolution to work. The online help was somewhat helpful but it still has not shown me enough that I can solve the problem. I think the problem has to do with the db.192.168. since this is a private address network. The root server is on one of the class c subnets and I think it has to do with the fact the root server has a 168.192.IN-ADDR.ARPA which would make it think that all of the subnets are in its domain so it should have the entries in its db.192.168 file. But the problem is it resides on the same subnet as the mn..com domain.

[Mark Seida]

I have the ptr records in the db.. Do I need some sort of entry in the revese db.192.168?

[Kamlesh Shete]

You should add ptr entries in the db.192.68

- KS

[Mark Seida]

The ptr records are in the db.192.168 file and I still have a problem doing reverse name resolution.

[Jordan Bean]

BIND 4.9.7... yuck. Try 8.9.3.

nslookup -type=soa 168.192.in-addr.arpa. ?
Is the zone configured in named.boot?
Does the serial for the zone need to be incremented?
Is the zone properly delegated?
Was named HUP'd?

[Wilfred Chau_1]

Did you try to use hosts_to_named?
If not, create a /etc/named.data directory.
create a file called param, or anything.
add this to param.
-d .com
-s your name server
-n 192.168
-d mn..com
-n ?.?
-d be..com
-n ?.?
-r your name server

Save the file, and do this,
cd /etc/named.data; hosts_to_named -f param
sig_named restart

[Jordan Bean · Accepted solution]

I'm tyring to visualize the setup:

In this isolated network, how many name servers are you running? Just the one root master? Or does each subdomain have a master server?

If just the one, the issue should be fairly trivial. The zone file for 168.192.in-addr.arpa would look like this:

$ORIGIN 168.192.in-addr.arpa.
@ IN SOA host.domain.com. hostmaster.domain.com. ( a b c d e )
IN NS host.domain.com.
1.1 IN PTR host.domain.com.
2.1 IN PTR host.mn.domain.com.
2.2 IN PTR host.be.domain.com.

But if you're maintaining the subdomains separately on other servers, then the root needs to delegate from both zones:

$ORGIN domain.com.
@ IN SOA ...
IN NS host.domain.com.
host IN A 192.168.1.1
mn IN NS host.mn.domain.com.
host.mn IN A 192.168.1.2
be IN NS host.be.domain.com.
host.be IN A 192.168.2.2

$ORIGIN 168.192.in-addr.arpa.
@ IN SOA ...
IN NS host.domain.com.
1.1 IN PTR host.domain.com.
1 IN NS host.mn.domain.com.
2.1 IN PTR host.mn.domain.com.
2 IN NS host.be.domain.com.
2.2 IN PTR host.be.domain.com.

I typed this up pretty quick so I'd expect errors.