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From: Arthur van Leeuwen arthurvl@sci.kun.nl
To: lartc@vger.kernel.org
Subject: [LARTC] 2 default gw in redhat 6.2
Date: Fri, 02 Feb 2001 09:32:01 +0000	[thread overview]
Message-ID: <marc-lartc-98373940416949@msgid-missing> (raw)
In-Reply-To: <marc-lartc-98373940416935@msgid-missing>

<PRE>On Fri, 2 Feb 2001, Rene 'Lynx' Pfeiffer wrote:

&gt;<i> On Thu, 1 Feb 2001, Arthur van Leeuwen wrote:
</I>&gt;<i>
</I>&gt;<i> &gt; On Thu, 1 Feb 2001, Rene 'Lynx' Pfeiffer wrote:
</I>&gt;<i> &gt;
</I>&gt;<i> &gt; &gt; On Thu, 1 Feb 2001, Arthur van Leeuwen wrote:
</I>&gt;<i> &gt; &gt;
</I>&gt;<i> &gt; &gt; &gt; On Thu, 1 Feb 2001, bert hubert wrote:
</I>&gt;<i> &gt; &gt; &gt;
</I>&gt;<i> &gt; &gt; &gt; &gt; Linux is supposed to have something called 'dead gateway detection'
</I>&gt;<i> &gt; &gt; &gt;
</I>&gt;<i> &gt; &gt; &gt; Which it doesn't use when there's a multipath default route. Now, that isn't
</I>&gt;<i> &gt; &gt; &gt; technically the case here, so that shouldn't be the problem here.
</I>&gt;<i> &gt; &gt;
</I>&gt;<i> &gt; &gt; Does this mean that Linux automatically detects a failed default
</I>&gt;<i> &gt; &gt; route and takes the second one if I configure two default routes?
</I>&gt;<i> &gt;
</I>&gt;<i> &gt; No, it means the exact opposite. If you configure two default routes
</I>&gt;<i> &gt; Linux will randomly multiplex outgoing connections over the two routes.
</I>&gt;<i>
</I>&gt;<i> This is exactly the problem I am having. I am trying to set up a spare default
</I>&gt;<i> route in case the primary route is down. The router in question is a Linux
</I>&gt;<i> machine having access to three upstream connections and to the DMZ. I do not
</I>&gt;<i> want to have routing daemons on the box, I simply want to change the default
</I>&gt;<i> route in case the primary connection (which supplies the LAN behind the DMZ)
</I>&gt;<i> is down.
</I>
&gt;<i> The only thing I have come up so far (I do not want to have fancy things like
</I>&gt;<i> zebra, routed or gated on this machine) is a Perl script that measures the
</I>&gt;<i> connectivity and takes action if it detects that the route is down.
</I>
&gt;<i> Does anyone have a better idea? (I am willing to to a nice and tidy ASCIIgram
</I>&gt;<i> if you like ;-)
</I>
Nope. Polling for connectivity is what you're stuck with doing, unless you
want to do some kernel hacking.

Doei, Arthur. (Who is thinking about actually doing the latter... it's
               *useful*, in more cases than one)

-- 
  /\    / |      <A HREF="mailto:arthurvl@sci.kun.nl">arthurvl@sci.kun.nl</A>      | Work like you don't need the money
 /__\  /  | A friend is someone with whom | Love like you have never been hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody watching



</PRE>

  parent reply	other threads:[~2001-02-02  9:32 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-02-01 19:49 [LARTC] 2 default gw in redhat 6.2 fabian1 fabian1
2001-02-01 21:06 ` bert
2001-02-01 21:18 ` Arthur
2001-02-01 21:29 ` Rene
2001-02-01 21:35 ` Arthur
2001-02-01 23:07 ` Rene
2001-02-02  9:32 ` Arthur [this message]
2001-02-02 13:44 ` Paul

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