From: David Wolsefer (dwolsefer@xxxxxxxx)
Date: Fri Jan 12 2001 - 21:39:55 GMT-3
Here is my real world dampening config. Alternatively, you can see Sam
Halabi's book "Internet Routing Architectures", p. 432 in the 2'nd edition.
The command syntax is as follows:
bgp dampening [[route-map map-name] [half-life-time reuse-value
suppress-value maximum-suppress-time]]
- half-life-time is in the range of 1 to 45 minutes. The current default is
15 minutes.
- reuse-value is in the range of 1 to 20000. The default is 750.
- suppress-value is in the range of 1 to 20000. The default is 2000.
- maximum-suppress-time is the maximum duration that a route can be
suppressed. The range is 1 to 255. The default is 4*half-life time.
For your specific problem, I would match the ip address for the route on the
interface serial 1. Hope this helps.
Cheers,
David Wolsefer, CCIE #5858
! Enable our dampening parameters. See the route map and prefix-lists
! below.
bgp dampening route-map graded-flap-dampening
!
! Now we configure our prefix lists for our dampening requirements.
! These are configured along the lines of the recommendations made
! by RIPE. The goal is to minimalize the effect of dampening on
! the shorter and historically more stable prefixes as well as the
! netblocks that contain DNS root servers. The longer prefixes
! are dampened for longer periods of time, as these have been the
! the source of a greater percentage of the instability in the
! global routing table.
! Note that a longer prefix equates to a less-aggregated and smaller
! netblock.
!
! The damplongprefixes list is for prefixes of /24 and longer.
ip prefix-list damplongprefixes description Prefixes of /24 and longer.
ip prefix-list damplongprefixes seq 5 permit 0.0.0.0/0 ge 24
!
! The dampmediumprefixes list is for prefixes of /22 and /23.
ip prefix-list dampmediumprefixes description Prefixes of /22 and /23.
ip prefix-list dampmediumprefixes seq 5 permit 0.0.0.0/0 ge 22 le 23
!
! The dampshortprefixes list is for prefixes of /21 and shorter.
ip prefix-list dampshortprefixes description Prefixes of /21 and shorter.
ip prefix-list dampshortprefixes seq 5 permit 0.0.0.0/0 le 21
!
! The rootservers prefix list is to prevent dampening of
! the root DNS server netblocks.
ip prefix-list rootservers description DNS root server netblocks.
ip prefix-list rootservers seq 5 permit 198.41.0.0/24
ip prefix-list rootservers seq 10 permit 128.9.0.0/16
ip prefix-list rootservers seq 15 permit 192.33.4.0/24
ip prefix-list rootservers seq 20 permit 128.8.0.0/16
ip prefix-list rootservers seq 25 permit 192.203.230.0/24
ip prefix-list rootservers seq 30 permit 192.5.4.0/23
ip prefix-list rootservers seq 35 permit 192.112.36.0/24
ip prefix-list rootservers seq 40 permit 128.63.0.0/16
ip prefix-list rootservers seq 45 permit 192.36.148.0/24
ip prefix-list rootservers seq 50 permit 193.0.14.0/24
ip prefix-list rootservers seq 55 permit 198.32.64.0/24
ip prefix-list rootservers seq 60 permit 202.12.27.0/24
!
! We apply our dampening prefix-lists with our route-map entries.
! Don't dampen the rootservers prefix-list.
route-map graded-flap-dampening deny 10
match ip address prefix-list rootservers
! Dampen the /24 and greater prefixes for a maximum of 60 minutes.
route-map graded-flap-dampening permit 20
match ip address prefix-list damplongprefixes
set dampening 30 750 3000 60
! Dampen the /22 to /23 prefixes for a maximum of 45 minutes.
route-map graded-flap-dampening permit 30
match ip address prefix-list dampmediumprefixes
set dampening 15 750 3000 45
! Dampen the /21 and shorter prefixes for a maximum of 30 minutes.
route-map graded-flap-dampening permit 40
match ip address prefix-list dampshortprefixes
set dampening 10 1500 3000 30
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Harbir Kohli
Sent: Friday, January 12, 2001 4:04 PM
To: 'Ccielab
Subject: bgp question
Hi
I am trying to configure bgp dampening if the interface serial 1 goes
down. I tried the following but it did not work. Does anyone know Why?
and What is the solution?
router bgp 10600
bgp confederation identifier 200
bgp confederation peers 10060
bgp dampening route-map damp
route-map damp permit 10
match interface Serial1
set dampening 20 950 2500 80
Thanks
Harbir
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