Re: Simple backup question

From: Mark D. Nagel (mnagel@willingminds.com)
Date: Mon Nov 05 2001 - 15:10:06 EST

Right -- in general, you need to use a dynamic routing protocol, since the
tunnel is considered up if the destination address is reachable (i.e., a route
exists to it). If you have a default route, then the destination is always
reachable. If you run OSPF over both tunnels and mark the backup tunnel with a
higher cost (for example, interface tun1, ip ospf cost 65), then the primary
tunnel will be used until the OSPF neighbor on tun0 goes away.

Mark 

--
Mark D. Nagel, CCIE #3177 <mnagel@willingminds.com>
Principal Consultant
Willing Minds LLC
Tel/Fax: 949-623-9853
Web: www.willingminds.com

----- Original Message -----
From: "Ilker Temir" <itemir@cisco.com>
To: "Birsen Ozturk" <birsen.ozturk@is.net.tr>
Cc: <cisco-nsp@puck.nether.net>
Sent: Monday, November 05, 2001 3:38 AM
Subject: Re: Simple backup question

> Selam Birsen,
>
> Actually this does not make sense. A tunnel intf. is always up and has no
> mechanism to detect if the tunnel destination is reachable or not (there are
no
> keepalives etc)
>
> If you want to pass traffic through tunnel1 when tunnel0 is unavailable you
can
> run a routing protocol (i.e ospf or eigrp) over tunnel 0 and use a floating
> static route for tunnel 1. But both tunnels will be up at the same time (even
> when the tunnel is not operational)
>
> Regards,
>
> - Ilker
>
> > Hello Everybody
> >
> > I have two tunnel interfaces:
> >
> > Tunnel0
> >        ip address 1.1.1.1 255.255.255.252
> >        tunnel source .....
> >        tunnel destination ....
> > Tunnel1
> >        ip address 2.2.2.2 255.255.255.252
> >        tunnel source ...
> >        tunnel destination ...
> >
> > I want Tunnel1 to track the state of Tunnel0 and to go up only when
> > Tunnel0 is down. How can I do that? Thank you in advance.
> >
> > Birsen Ozturk
> >
>
>

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