3Com Switch 7750 Configuration Guide Guide

346 CHAPTER 36: BGP CONFIGURATION
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CAUTION: BGP-IGP route synchronization is not supported on 3Com Switch 7750
Family Ethernet switches.
Configuring BGP Route
Dampening
Route dampening is used to solve the problem of route instability. Route instability
mainly refers to route flapping. A route flaps if it appears and disappears
repeatedly in the routing table. Route flapping increases the number of BGP
update packets, consumes the bandwidth and CPU time, and even decreases
network performance.
Assessing the stability of a route is based on the behavior of the route in the
previous time. Once a route flaps, it receives a certain penalty value. When the
penalty value reaches the suppression threshold, this route is suppressed. The
penalty value decreases with time. When the penalty value of a suppressed route
decreases to the reuse threshold, the route gets valid and is thus advertised again.
BGP dampening suppresses unstable routing information. Suppressed routes are
neither added to the routing table nor advertised to other BGP peers.
Configuring BGP Load
Balance
Enable BGP, and enter BGP
view
bgp as-number
Required
By default, BGP is disabled.
Disable BGP-IGP route
synchronization
undo synchronization
Required
By default, BGP routes and
IGP routes are not
synchronized.
Table 279 Configure BGP-IGP route synchronization
Operation Command Description
Tabl e 280 Configure BGP route dampening
Operation Command Description
Enter system view system-view -
Enable BGP, and enter BGP
view
bgp as-number
Required
By default, BGP is disabled.
Configure BGP route
dampening-related
parameters
dampening [
half-life-reachable
half-life-unreachable reuse
suppress ceiling ] [
route-policy
route-policy-name ]
Optional
By default, route dampening
is disabled. Other default
route dampening-related
parameters are as follows.
■ half-life-reachable: 15 (in
minutes)
■ half-life-unreachable: 15
(in minutes)
■ reuse: 750
■ suppress: 2000
■ ceiling: 16,000
Tabl e 281 Configure BGP load balance
Operation Command Description
Enter system view system-view -