From: Dave Gahm (gahm@xxxxxxx)
Date: Fri Mar 31 2000 - 13:31:42 GMT-3
Kevin,
The BGP rule of synchronization state that if a route is learned from IBGP,
it must already be known by the IGP to be entered into the routing table. It
is not enough for the next hop to be in the table, the router must already
know how to reach that network. The reason for this is that traffic could be
black-holed if your AS is handling transit traffic and not all your internal
routers are running BGP. To get around this use the "no sync" command in
your BGP config.
Regards, Dave
-----Original Message-----
From: Kevin Gannon <kevin@gannons.net>
To: Ccielab@Groupstudy.Com <ccielab@groupstudy.com>
Date: Friday, March 31, 2000 5:53 AM
Subject: BGP No best path ?
>I have a config where I am seeing BGP routes appearing and then a few
>moments
>latter they are being purged from the route table for the message (debugs
>on)
>
>00:49:23: BGP: no valid path for 10.10.10.0/24
>00:49:23: BGP: no valid path for 41.1.2.0/24
>00:49:23: BGP: no valid path for 137.20.44.1/32
>00:49:23: BGP: no valid path for 200.200.200.0/24
>
>The next hop router is reachable via a IGP and the hub of the network can
>see
>the peer. The update source is a loopback on both sides. Anyone any ideas ?
>
>Regards,
>Kevin
>
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