[c-nsp] OSPF Dampening
Jeremiah Millay
jeremiah at rockriver.net
Fri Sep 29 10:02:15 EDT 2006
In BGP there is a mechanism to dampen routes from a peer that is
flapping. Does anything similar to this exist for OSPF on a Cisco router?
The closest thing I can find is this (IP Event Dampening):
http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide09186a0080110bc8.html
...but it won't work for my setup because my interfaces don't flap, only
the OSPF adjacency is flapping.
Here is a crude diagram of my setup:
(a)------(b)
\ /
\ /
(c)
-Router A's primary path to router C is through B. This connection is
through a point-to-point wireless connection fed to the routers via ethernet
- When the conenction from router A to B goes down, the link from A to C
is to become active.
I'm having problems with the radios failing between router A and B.
Because the ethernet link never goes down and it still receives hellos
sporadically the link from A to C never becomes active. On router A I
get log output similar to the following (and it repeats over and over):
*Sep 28 17:05:55: %OSPF-5-ADJCHG: Process 1, Nbr X.X.X.X on
FastEthernet0/0 from LOADING to FULL, Loading Done
*Sep 28 17:06:56: %OSPF-5-ADJCHG: Process 1, Nbr X.X.X.X on
FastEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired
*Sep 28 17:07:24: %OSPF-5-ADJCHG: Process 1, Nbr X.X.X.X on
FastEthernet0/0 from LOADING to FULL, Loading Done
*Sep 28 17:09:03: %OSPF-5-ADJCHG: Process 1, Nbr X.X.X.X on
FastEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired
*Sep 28 17:09:20: %OSPF-5-ADJCHG: Process 1, Nbr X.X.X.X on
FastEthernet0/0 from LOADING to FULL, Loading Done
*Sep 28 17:10:44: %OSPF-5-ADJCHG: Process 1, Nbr X.X.X.X on
FastEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired
I would like to be able to dampen the routes from a neighbor when the
interface itself does not flap but the adjacency flaps. Is there any way
to do this or am I outta luck?
Thanks in advance,
Jeremiah
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