resolve hostname outside my domain

[Andrey G. Sergeev (AKA Andris)]

Hello Karsten,


Sun, 17 Aug 2008 03:37:59 -0700 (PDT) orak wrote:

> Hello!
> I have the following problem in the following situation (little
> simplified).
> 
> ------------Internet------------
>                            |
>                            |        (external name: hhbgate.bonn.de)
>                          Gateway
>                            |        (internal name:
> hhbgate.hhb.bonn.de)
>                            |
>                           --------------- local net, we use
> hhb.bonn.de as domain name
> 
> on the gateway we use bind as dns.
> Sometimes (not very often) the connection to the internet is down.
> The following problem: internal user ask for http://hhbgate.bonnn.de/
> If the internet-connection is up -> no problem
> if the internet-connection is down -> no response
> That ist not surprising but a problem to me. We use an e-learning
> system named moodle which requires
> a name of the site: we take hhbgate.bonn.de. So if our internet is
> down we can't use moodle.
> 
> My question: is it possible to configure bind so that it resolves a
> single name outside my domain.
> I found only the hint that it is not possible to use an alias for a
> name outside my domain.

I assume that you're using BIND at you gateway as a caching-only server. 
The "hhbgate.bonn.de" label is a hostname (IN A), not a zone delegation 
point. In this case the simplest and the quickest method to still 
resolve this hostname to its IP address is to modify your named.conf 
like this:

named.conf:

zone "hhbgate.bonn.de" IN {
	type master;
	file "path-to-zone-files/hhbgate.bonn.de.db";
	notify no;
};

path-to-zone-files/hhbgate.bonn.de.db:

$ORIGIN hhbgate.bonn.de.
$TTL 86400
@		IN SOA		hhbgate.bonn.de. mailbox.domain.tld. (
				2008081800
				43200
				3600
				604800
				10800
		)
@		IN NS		hhbgate.bonn.de.	; or localhost
@		IN A		195.37.161.22

A more complex but also more powerful way is to implement views. There 
are also some other possible ways to address your issue but they seem to 
be not convenient as the previous two.


-- 

Yours sincerely,

Andrey G. Sergeev (AKA Andris)     http://www.andris.name/