Operation Manual – Routing Protocol
H3C S5600 Series Ethernet Switches
Chapter 5 BGP Configuration
5-25
To do...
Use the command...
Remarks
Disable BGP-IGP route
synchronization
undo synchronization
Required
By default, BGP routes
and IGP routes are not
synchronized.
Caution:
BGP-IGP route synchronization is not supported on the switches.
5.4.8 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.
Follow these steps to configure BGP route dampening:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter BGP view
bgp
as-number
—
Configure BGP
route
dampening-related
parameters
dampening
[
half-life-reachable
half-life-unreachable
reuse suppress ceiling
]
[
route-policy
route-policy-name
]
Optional
Not configured by default.
The defaults are as follows:
z
half-life-reachable: 15 (in
minutes)
z
half-life-unreachable: 15 (in
minutes)
z
reuse: 750
z
suppress: 2000
z
ceiling: 16000