topic Re: DNS forwarding in Operating System - Linux

DNS forwarding

Zigor Buruaga — Sun, 14 Feb 2010 20:05:51 GMT

Hi,

I have installed BIND 9 in my opensuse at home in order to test how the forwarding works.
What i want to do is to reject any dns query except the domains I want to resolve. I have deleted the configuration of “root.hint” file and configured /etc/named.conf with a zone like this:

zone "wikipedia.org" in {

type forward;

forward only;

forwarders { my_ISP_dns_1; my_ISP_dns_2; };

I don't show my ISP DNS's ip addresses to protect the innocent.

I restart the named service and seems to be okay, I can resolve “wikipedia.org” and nothing else.
However, I was expecting to resolve also “es.wikipedia.org” ... but that's not working. Is there a way to tell bind to resolve domains without creating a zone file with all the possibilities?.

I'm not familiar with dns stuff so i'd appreciate any help.

Thanks in advance,
Zigor

Re: DNS forwarding

Matti_Kurkela — Mon, 15 Feb 2010 08:05:21 GMT

$ nslookup es.wikipedia.org
Server: 127.0.0.1
Address: 127.0.0.1#53

Non-authoritative answer:
es.wikipedia.org canonical name = rr.wikimedia.org.
rr.wikimedia.org canonical name = rr.esams.wikimedia.org.
Name: rr.esams.wikimedia.org
Address: 91.198.174.2

Looks like es.wikipedia.org is an alias, pointing to another alias, pointing to rr.esams.wikimedia.org.

I seem to recall that pointing aliases to aliases was not recommended... but I guess you probably aren't in a position to fix this. Anyway, it obviously *can* be made to work.

To resolve "es.wikipedia.org", your server must be able to resolve "wikimedia.org" too. If the server is prevented from doing that, it cannot resolve the alias chain, and therefore cannot provide an answer to the client's request.

MK

Re: DNS forwarding

Zigor Buruaga — Mon, 15 Feb 2010 13:11:18 GMT

You got it, that solved my problem ( to be honest i didn't realized that is wikimedia, not wikipedia ), very helpful response.

Thanks much,
Zigor

Re: DNS forwarding

Zigor Buruaga — Mon, 15 Feb 2010 13:12:35 GMT

Thanks much for the help.

Regards,
Zigor