resolver problems

[Kevin Darcy]

Well, depending on what resolver you're running, you could try to tune your
resolver configuration to make the timeout smaller.

The only *comprehensive* solution that comes to mind, however, is to run your
own root zone when you are disconnected from the Internet. This solution would
require you to perform some sort of automatic nameserver reconfiguration every
time you connect or disconnect from the Internet.

If you wanted to get fancy with this, you could even put a wildcard entry in
the zone, directing people to a web page (telnet shell, FTP server, whatever)
informing users that the Internet connection is down and to try again later.


- Kevin

Wim.Holemans wrote:

> [ This is a repost of the following article:                               ]
> [ From: "Wim.Holemans" <holemans at hnets.uia.ac.be>                          ]
> [ Subject: resolver problems                                               ]
> [ Newsgroups: comp.protocols.tcp-ip.domains                                ]
> [ Message-ID: <39fed3d0 at news.uia.ac.be>                                    ]
>
> Situation :
> machine with primary nameserver for domain x.y.z
> /etc/resolv.conf :
> domain x.y.z
> nameserver 127.0.0.1
>
> We experience some dns problems whenever our connection the the internet
> (to the root servers) is down :
> when someone does a   ping <machine> (and machine is a not existing hostname
> in the domain x.y.z) the process hangs with a very large
> timeout when our outgoing connection is down.
> I did a debug and found out that the resolver is trying to resolve
> <machine> first (with the root servers) and then tries <machine>@x.y.z
> If our connection to the internet is down, the first resolving seems to take
> forever hanging the applications.
>
> I changed the domain command in the resolver file with
> search x.y.z.   and now the resolving is done the other way around :
> <machine>@x.y.z  and then <machine> if <machine>@x.y.z doesnt't exist.
>
> Is there a way to specify that only <machine>@x.y.z should be resolved
> and not <machine> ?  So no outside dns consulting if no domain is
> given ?
>
> Thanks,
>
> -----------------------------------------------------------------------
> Wim Holemans                            phone + 32 3 820 22 03
> Network/System manager                  fax   + 32 3 820 22 44
> U.I.A.                         e-mail : wim.holemans at uia.ua.ac.be
> University of Antwerp Belgium  http://www.uia.ua.ac.be/u/holemans
> -----------------------------------------------------------------------
>
> -----------------------------------------------------------------------
> Wim Holemans                            phone + 32 3 820 22 03
> Network/System manager                  fax   + 32 3 820 22 44
> U.I.A.                         e-mail : wim.holemans at uia.ua.ac.be
> University of Antwerp Belgium  http://www.uia.ua.ac.be/u/holemans
> -----------------------------------------------------------------------