[Savannah-hackers-public] Re: [gnu.org #437069] Reverse DNS resolution

[Sylvain Beucler]

On Fri, May 01, 2009 at 03:11:35PM -0400, Ward Vandewege via RT wrote:
> > [beuc - Fri May 01 14:43:25 2009]:
> > Did anything change in the reverse DNS resolution setup recently?
> 
> I changed our nameserver configuration to no longer respond to lookups
> for '.', as per
> 
>   http://isc.sans.org/diary.html?date=2009-01-18
> 
> That change was made on 2009-04-27.
> 
> But that *should* be unrelated.
> 
> > Savannah uses 10.0.0.0/24 internally and some processes do reverse
> > lookup on them.  When I try to do the reverse manually, all DNS
> > servers eventually timeout, but this takes a very long while.  MySQL
> > in particular was impacted AFAIK.
> 
> Yeah. The problem is clearly these reverse lookups. But, arguably you
> shouldn't be sending those lookups to nameservers in /etc/resolv.conf
> (only one of which is FSF operated, the others are run by our ISP).
> 
> Can you add /etc/hosts entries to work around this?

I can and will, but in order to avoid such mysterious issues again,
would it be possible to send a reject or anything but not drop the
request?

-- 
Sylvain