[c-nsp] Mysterious GRE tunnel flap

[Gert Doering]

Hi,

On Wed, Jul 21, 2010 at 07:33:56PM -0600, Quinn Kuzmich wrote:
> To make this stranger, it's only ONE end of the tunnel going down.  
> The other side stays up.

That's not overly surprising as there is no signalling protocol on a GRE
tunnel (unless keepalives are configured) that could affect this.

My bet is that you're losing the route to the tunnel destination for a
moment, for whatever reason - and then IOS will make the tunnel "down".

Try setting up "debug ip routing" (caveat: don't do this on a box that
has a full Internet routing table, or lots of other instabilities in its
routing table).

gert
-- 
USENET is *not* the non-clickable part of WWW!
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Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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