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EIGRP / OSPF dampening


From: Donn Lasher <dlasher () clearskynet net>
Date: Tue, 17 Dec 2002 18:02:48 -0700



I'm looking for a way to way to either dampen, penalize, or otherwise slow down a flapping interface, when the router has no "link state" information about the Layer 2 connection, which is itself causing the flap... Example...

Dec 17 08:23:50 xxx.xxx.xxx.xxx 2106: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is down: peer restarted Dec 17 08:23:52 xxx.xxx.xxx.xxx 2107: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is up: new adjacency Dec 17 08:24:09 xxx.xxx.xxx.xxx 2108: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is down: peer restarted Dec 17 08:24:11 xxx.xxx.xxx.xxx 2109: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is up: new adjacency Dec 17 08:24:42 xxx.xxx.xxx.xxx 2110: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is down: peer restarted Dec 17 08:24:43 xxx.xxx.xxx.xxx 2111: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is up: new adjacency Dec 17 08:25:18 xxx.xxx.xxx.xxx 2112: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is down: peer restarted Dec 17 08:25:20 xxx.xxx.xxx.xxx 2113: 15w5d: %DUAL-5-NBRCHANGE: IP-EIGRP 10: Neighbor xxx.xxx.xxx.xxx (FastEthernet2/0.3) is up: new adjacency

This type of flapping yields an effectively down interface, yet, appears "up" so data gets blackholed while dead timers expire, etc.

I'm very familar with doing this via BGP, but haven't found any good way yet to do this with either EIGRP or OSPF.

Any ideas? Feel free to either reply to the list, or privately.

Thanks in advance..


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