Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?




Hierarchy Level


Enables equal-cost multipath (ECMP) fast reroute protection. If a link fails, ECMP uses fast reroute protection to shift packet forwarding to operational links to reduce packet loss. Fast reroute protection updates ECMP information for the interface without waiting for route table updates. When the next route table update occurs, a new set of ECMP interfaces are added with fewer links, or the route points to a single next hop.

Without ECMP fast reroute protection, upon link failure the creation of the new ECMP set is delayed while the routing table information is updated. Once the new ECMP set is created, the hashing algorithm calculates new paths. Enabling the ecmp-fast-reroute option eliminates the routing table convergence delay.

ECMP is a global configuration and will impact only the nexthop addresses learnt after the ECMP configuration. However, the existing nexthop addresses are not impacted. Therefore, you must either remove the existing configuration and restore it along with the fast reroute configuration or you can restart routing or the linecard. You can also reboot the device to add the ECMP fast reroute links for the existing nexthop addresses.


ECMP works differently with indirect next hops. Please see ECMP Flow-Based Forwarding for more information.

Required Privilege Level

routing—To view this statement in the configuration.

routing-control—To add this statement to the configuration.

Release Information

Command introduced before Junos OS Release 17.4.