Configuring EVPN route flapping suppression helps mitigate the impact of EVPN route instability on running services.
Route flapping is a major symptom of EVPN route instability. When an EVPN route flaps, it repeatedly disappears from the routing table and then reappears. EVPN route flapping consumes lots of bandwidth and CPU resources and even affects the normal network operation in extreme cases.
EVPN supports EVPN route flapping suppression through route dampening, which uses a penalty value to reflect the stability of an EVPN route. When an EVPN route flaps, it is assigned a penalty value. A greater number of flapping times indicates a larger penalty value. If the penalty value exceeds the preset threshold, the EVPN route is not advertised. When the penalty value decreases to the reuse threshold after a period of time, the EVPN route is re-advertised.
Before configuring EVPN route flapping suppression, complete one of the following tasks:
The system view is displayed.
The BGP view is displayed.
The BGP EVPN address family view is displayed.
The reuse, suppress, and ceiling values must meet the following requirement: reuse value < suppress value < ceiling value.
After a route-policy is specified, EVPN can use different route dampening parameters to suppress different routes.
The configuration is committed.
After completing the configuration, perform the following operations to verify it:
To clear the dampening information about EVPN routes and release suppressed EVPN routes, run either of the following commands as needed:
To clear statistics about EVPN route flapping, run any of the following commands as needed: