Google ADs
A route is considered to be flapping when its availability changes repeatedly.Route Dampening is a way to suppress flapping routes so that they are “suppressed” instead of being advertised.
Since BGP routing tables are huge, it’s not practical to send those routing updates to all the routers especially when a route flap occurs. This could affect the performance of the network as well as consume more routers resources like CPU. As a best practice most ISPs use route dampening regularly.
In this scenario, BGP route dampening will be configured on Router R1 as below –
Google ADs
To Configure R1 and use BGP dampening as per following parameters –
- Penalty should be reduced by half after 10 minutes
- The dampened route must be reused when it reaches value of 750.
- Route should not be used when it reaches 2000 points.
- The routes experiencing Route flaps should not be suppressed for more than 40 minutes
R1(Config)#
router bgp 1
no synchronization
bgp log-neighbor-changes
bgp dampening 10 750 2000 40
network 1.1.1.0 mask 255.255.255.0
network 192.168.12.0
neighbor 192.168.12.2 remote-as 2
no auto-summary
router bgp 1
no synchronization
bgp log-neighbor-changes
bgp dampening 10 750 2000 40
network 1.1.1.0 mask 255.255.255.0
network 192.168.12.0
neighbor 192.168.12.2 remote-as 2
no auto-summary
R1#show ip bgp dampening parameters
dampening 10 750 2000 40
Half-life time : 10 mins Decay Time : 1550 secs
Max suppress penalty: 12000 Max suppress time: 40 mins
Suppress penalty : 2000 Reuse penalty : 750
dampening 10 750 2000 40
Half-life time : 10 mins Decay Time : 1550 secs
Max suppress penalty: 12000 Max suppress time: 40 mins
Suppress penalty : 2000 Reuse penalty : 750
ABOUT THE AUTHOR
Founder of AAR TECHNOSOLUTIONS, Rashmi is an evangelist for IT and technology. With more than 12 years in the IT ecosystem, she has been supporting multi domain functions across IT & consultancy services, in addition to Technical content making.
You can learn more about her on her linkedin profile – Rashmi Bhardwaj
