[Samba] Problem with multiple dns forwarders -timeout is too big - how to change?

[Rowland Penny]

On Tue, 17 Dec 2024 11:02:09 +0100
Luis Peromarta via samba <samba at lists.samba.org> wrote:

> +1
> 
> Would you believe, right about an hour ago, one of my forwarders
> died, and I had the exact same problem !
> 

Looking at the code, it seems (from my understanding) that any unknown
addresses outside the AD dns domain are forwarded to the first external
server in 'dns forwarder', if there is an error, it tries the next in
line until it runs of forwarders.

There must be some 'timeout' involved, but my understanding of 'C' is
limited and when multiple dns forwarders was added (4.5.0), the release
notes said this:

Previously, the Samba internal DNS server supported only one DNS
forwarder. The "dns forwarder" option has been enhanced and now
supports a space-separated list of multiple DNS server IP addresses. As
a result, Samba is now able to fall back to alternative DNS servers. In
case that a DNS query to the first server timed out, it is sent to the
next DNS server listed in the option.

You can add an option to /etc/resolv.conf on the forwarder to reduce the
'timeout' (which I think is 10s as standard), but this wouldn't be much
good if the forwarder isn't there, for whatever reason.

I think you would get the same behaviour if you used bind9 with
forwarders.  

Rowland