Tools for detecting a dead server and deactivating the corresponding name entry

[Kevin Darcy]

The basic concept doesn't seem too difficult:

#!/bin/sh

for ipaddr in $ipaddr1 $ipaddr2
do
    down=`ping $ipaddr 1 1 | grep '100% packet loss'`
    if [ -n "$down" ]
    then
        (
            echo update delete $name a $ipaddr
            echo
        ) | nsupdate
    fi
done

How's that for "cheap"? But obviously, for production use, one should make it
a lot more sophisticated...

Of course, the big caveat about this whole approach is that caching-only
nameservers around the Net may not see the change for a while and so the
browsers and/or proxies they serve will still try to bang on the dead web
server.


- Kevin

Christoph Wagner wrote:

> I am searching for an add-on I would say. Distributed Director is a really
> expensive hardware solution.
> Anybody who knows a "cheap" easy tool which can detect inactive service and
> change name entries?
>
> PS:  http://www.eddieware.org/old/dns_server.html  is not reachable.
>
> Regards,
> Chris
>
> ----- Original Message -----
> From: "Ron Pitts" <ron.pitts at claripoint.com>
> To: <bind-users at isc.org>
> Sent: Friday, February 23, 2001 12:30 PM
> Subject: Re: Tools for detecting a dead server and deactivating the
> corresponding name entry
>
> >
> >
> >
> > Have a look at http://www.eddieware.org/old/dns_server.html  I remember
> they
> > had some sort of add-on for BIND to allow load balancing similar to round
> > robin.
> >
> >
> >
> >
> > -----Original Message-----
> > From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org]On
> > Behalf Of Jim Reid
> > Sent: 23 February 2001 10:43
> > To: Christoph Wagner
> > Cc: bind-users at isc.org
> > Subject: Re: Tools for detecting a dead server and deactivating the
> > corresponding name entry
> >
> >
> > >>>>> "Christoph" == Christoph Wagner <christoph-w at gmx.at> writes:
> >
> >     Christoph> Hi, In normal operation the name server resolves using
> >     Christoph> round robin between the multiple entries.  I want a
> >     Christoph> solution to check if a server is ok and if one of them
> >     Christoph> is down the name server should stop resolving this
> >     Christoph> address.
> >
> > There are commercial products like Cisco's Distributed Director which
> > do this. Regular DNS software doesn't.
> >
> >
> >