Re: weird BGP cisco-ism? [problem resolved]
Original message <199707112126.RAA11467@home.partan.com> From: Andrew Partan <asp@partan.com> Date: Jul 11, 17:26 Subject: Re: weird BGP cisco-ism? [problem resolved]
provider, and we have "summary-only" set in our BGP configuration. Every
Try it w/o the summary-only stuff.
Didn't help at all.
I don't use summary-only, or aggregate-address, or network XXX at all. I redis my connected & static routes into bgp and arrange for my global routes to make it beyond my AS. I also use pull up static routes to null0 for all of my blocks.
I redistribute in a similar way, and have the statics to null0 as well. Still insisted on flapping at least twice every time it got the brief hit on the /24 subnet coming from the outside world. At this point what needs to happen is for this to be recreated in a lab somewhere and some config changes tried... I can't blow away my customers one more time just to play with it. Some day we'll have routers that can tell you what they're doing, right? -matthew
On Fri, 11 Jul 1997, Matthew Kaufman wrote: ==>I redistribute in a similar way, and have the statics to null0 as well. ==> ==>Still insisted on flapping at least twice every time it got the brief ==>hit on the /24 subnet coming from the outside world. What routing protocol do you use? If you're using a protocol which uses a hold-down (read: RIP), the holddown period causes the route to be withdrawn while marked as inaccessible in the IGP, and re-announced when the hold-down period goes away and the static route gets inserted. /cah
Craig A. Huegen wrote:
On Fri, 11 Jul 1997, Matthew Kaufman wrote:
==>I redistribute in a similar way, and have the statics to null0 as well. ==> ==>Still insisted on flapping at least twice every time it got the brief ==>hit on the /24 subnet coming from the outside world.
What routing protocol do you use? If you're using a protocol which uses a hold-down (read: RIP), the holddown period causes the route to be withdrawn while marked as inaccessible in the IGP, and re-announced when the hold-down period goes away and the static route gets inserted.
You might try "no synchronization" in BGP. It solved some flapping for me that I was getting between a pair of routers where the paths were always getting marked inaccessible. My situation was different than this but it seems to have enough similarity that maybe... -- Phil Howard KA9WGN +-------------------------------------------------------+ Linux Consultant | Linux installation, configuration, administration, | Milepost Services | monitoring, maintenance, and diagnostic services. | phil at milepost.com +-------------------------------------------------------+
participants (3)
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Craig A. Huegen -
matthew＠scruz.net -
Phil Howard