reverse lookups for 192.168 network not working

[Kevin Darcy]

hugo wrote:

> Hi
>
> I have set up DNS on a Linux RedHat 7.3 server running bind-9.2.0-8. I
> also set up a private network 192.168.1.0/256. The DNS server is also
> the gateway for that domain, i.e it has a presence in that domain.
>
> I can do name lookups on that domain as long as I supply the full domain
> name of the computer I want to look up, e.g. if I supply
> "ono.fractaltechnologies.com" as the name for which to look up the IP
> address it works, but not if I supply "ono" by itself.
>
> However, I cannot do reverse lookups at all - nor with "dig -x" nor with
> nslookup. When I do this for an IP, e.g. 192.168.1.3 I get an address
> somewhere else - presumably for a private domain to which (wrongly)
> access from outside is possible.
>
> As far as I can see I have set up all my DNS files correctly, including
> the named.conf file. Can anyone tell me what I should do to:
>
> 1. Enable reverse lookups for computers in the 192.168.1.0/256 domain?

(256 bits of netmask? That's even beyond the capability of IPv6!).

If you use private address ranges like 192.168/16, and you use DNS, then
you *must* set up the relevant reverse domain(s) in DNS. The rest of the
Internet doesn't want or need your bogus queries.

> 2. Enable lookups by computer name only (without domain extension).

That's not a nameserver function; it's a resolver function. Check out the
"domain" directive for /etc/resolv.conf. Or, better yet, educate your users
to use only fully-qualified names.


- Kevin