Strang name resolution behavior

Stefan Puiu stefan.puiu at
Thu Apr 20 09:40:20 UTC 2006

OK, then please try running any of the commands that require
resolution (at least ping doesn't seem to like to be straced on my
machine, but you can try ssh for example), and then look for
connect()/send() calls in the output, and see which IP is used there.
You could also try using tcpdump to verify that there is no traffic
whatsoever being sent.


On 4/20/06, Dr. Harry Knitter <harry at> wrote:
> Really, this is not the first bind I have configured.
> When I insert the entries in /etc/hosts everything is resolved perfectly.
> Without these entries the behaviour described can be noticed
> > Also, you said that dig/host
> > work, but not normal programs, now the only differences I can think of
> > are that 1) normal programs go through the resolver library, which
> > will read /etc/hosts before doing an actual query (because of what you
> > have in /etc/nsswitch.conf)
> The normal behaviour would be in this case
> first query /etc/hosts; if this fails; query bind
> changing the sequence in nsswitch.conf would result in
> first query bind; if this fails; query /etc/hosts
> > and 2) the domain would be appended on all
> > non fully qualified queries (i.e. somehost as opposed to
> > somehost.mydomain.local.).
> >
> I tried that with FQDNs an short names: same thing because search
> <domain-name> entry exists in resolv.conf
> > How does ping fail?
> unknown host <machine | CNAME>.mydomain.local
> > Are you sure it doesn't get to query the
> > nameserver?
> As already posted there are no entries in query log at all when pinging, the
> host commands are recorded.
> If I try the same from a M$-client all queries are recorded in query log.
> > Can you try tracing if there are any packets sent using
> > tcpdump? Or alternatively, use strace to see what actually happens
> > when ping needs to resolve?
> >
> > How are your applications failing? Are they timing out on all queries?
> yes
> > Do your Windows clients have a default domain defined, just like the
> > Windows ones?
> yes
> Regards
> Harry

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