Re: Bind behaves weirdly

On Dec 27, 2004, at 3:06 PM, jc pinoteau wrote:

> I am using bind 9.2.3 for caching only on several gateways with
> different
> ISPs. On one of them I get weird results. It won't resolve google.com
> (for
> instance) for a few hours then it would do it again (without any
> action from
> my part). It will give the same result as if I was digging on a non
> existing
> domain.
>
> It is not a problem with the ISP as digging on the ISP's DNS returns a
> good
> result.
>
> If I restart bind it works again.
>
> How can I analyse what is happening?

You can use "dig" with a "+trace" option to give more complete DNS
resolution information.

> options {
> forward first;
> forwarders {
> 195.68.0.1;
> 195.68.0.2;
> };
> };
>

Are you sure that your "forwarders" statement is correct. You have
identified 192.68.0.1 and 192.68.0.2 as the servers that you are
forwarding to. Just guessing, are you sure that you don't want
192.168.0.1 and 192.168.0.2 as your forwarders? (The 192.68.0.0
network belongs to a German organization. These addresses don't
respond to DNS queries so I suspect that they aren't functioning DNS
servers.)

Then again, since you are running your own DNS servers, do you really
need to have these "forward first"/"forwarders" sections at all? There
are many times that trying to specify a forwarding system for DNS
causes more problems than it solves.

> // a caching only nameserver config

.... stuff removed ...

> // workaround stupid stuff... (OE: Wed 17 Sep 2003)

Why try and incorporate "stupid stuff" into a server configuration. If
you need it, it isn't stupid. If you don't need it, don't have it in
the configuration. (If you aren't sure that you need it, try
commenting it out and see if things still work. If you don't need it
to function then you can either leave it commented out or simply delete
it.)

I'm a strong believer in the KISS principle, even with DNS. There
shouldn't need to be any magic in your configuration, including
forwarding. (Disclaimer: There are times when forwarding is necessary,
but these are the exception and not the rule.)

Bill Larson