Re: Resolver not always resolving hostnames

Simon L. Nielsen wrote:
> Hey,
>
> I think something odd is going on in the resolver.  It seems like it
> doesn't resolve hostnames some of the time.  It's not really easily
> reproducible, but I have seen it happen several times with cvsup where
> it can't resolve the cvsup server.  If I re-run cvsup it works fine.
>
> I see it on recent -CURRNET's (server running cvsup below is October
> 12, system running host(1) is October 15).
>
> The cvsup log:
>
> CVSup update begins at 2006-10-18 17:29:00
> Updating from cvsup3.dk.freebsd.org
> Name lookup failure for "cvsup3.dk.freebsd.org": Host name lookup failed
> Updating local ncvs
> CVSup update ends at 2006-10-18 17:29:01
>
> I also seen odd things happen with host(1).  These two commands were
> run right after each other.  I don't know if it's related, but I
> suspect it is.
>
> $ host cvsup3.dk.freebsd.org
> cvsup3.dk.freebsd.org is an alias for mirror03.inet.tele.dk.
> cvsup3.dk.freebsd.org is an alias for mirror03.inet.tele.dk.
> $ host cvsup3.dk.freebsd.org
> cvsup3.dk.freebsd.org is an alias for mirror03.inet.tele.dk.
> mirror03.inet.tele.dk has address 195.41.53.219
> cvsup3.dk.freebsd.org is an alias for mirror03.inet.tele.dk.
> cvsup3.dk.freebsd.org is an alias for mirror03.inet.tele.dk.
>
> I only have one name-server in resolv.conf, so the problem isn't due
> to hitting different caching name-servers.
>
> Initially I thought it was a local problem for me, but joel_at_ has seen
> the same on RELENG_6 (from July 8), and xride_at_ has seen the
> same/similar with csup where his workaround was to ping the cvsup
> server before running csup.
>
> So, has anyone seen anything similar?  Since I can't reproduce the
> issue at will I don't really know where to look for what's going on,
> and of course it could be DNS issue...
>
>   
Same here with csup vs. cvsup.hu.FreeBSD.org. If I resolve it elsewhere 
and specify the ip address manually, it works just fine. Tomorrow's 
-current here on i386.

-- 
Cheers,

Gabor