OSPF Prefix Suppression Considerations
OSPF prefix suppression is a feature that can be selectively enabled on specific routers within an OSPF network to reduce unnecessary LSA propagation. It is most effective when configured on:
- Transit routers: These routers forward traffic between other routers in the network.
- Designated Routers (DRs) in broadcast networks: The DR is responsible for generating and distributing LSAs for the broadcast segment.
Enabling prefix suppression on these strategic points prevents the propagation of transit prefix LSAs throughout the OSPF domain, which can lead to improved network efficiency and reduced control plane overhead.
It is not necessary or recommended to enable prefix suppression on all routers in the OSPF network. Instead, it should be implemented thoughtfully on key routers to achieve the desired reduction in LSA flooding while maintaining proper network functionality.
Prefix suppression can be configured either globally using the prefix-suppression command within the OSPF router configuration mode, or on a per interface basis using the ip ospf prefix-suppression command within interface configuration mode.
Links:
https://forum.networklessons.com/t/ospf-prefix-suppression/1978/22?u=lagapidis
https://networklessons.com/cisco/ccie-routing-switching-written/ospf-prefix-suppression