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Hierarchy Level


Fast failover (that is, sub-50ms switch over for C-multicast streams as defined in Draft Morin L3VPN Fast Failover 05, ) is supported for MPC cards operating in enhanced-ip mode that are running next generation (NG) MVPNs with hot-root-standby enabled.

Live-live NG MVPN traffic is available by enabling both sender-based reverse path forwarding (RPF) and hot-root standby. In this scenario, any upstream failure in the network can be repaired locally at the egress PE, and fast failover is triggered if the flow rate of monitored traffic falls below the threshold configured for min-rate.

On the egress PE, redundant multicast streams are received from a source that has been multihomed to two or more senders (upstream PEs). Only one stream is forwarded to the customer network, however, because the sender-based RPF running on the egress PE prevents any duplication.

Note that fast failover only supports VRF configured with a virtual tunnel (VT) interface, that is, anchored to a tunnel PIC to provide upstream tunnel termination. Label switched interfaces (LSI) are not supported.


min-rate is not strictly supported for MPC3 and MPC4 line cards (these cards have multiple lookup chips and an aggregate value is not calculated across chips). So, when setting the rate, choose a value that is high enough to ensure that lookup will be triggered at least once on each chip every 10 milliseconds or less. As a result, for line cards with multiple look up chips, a small percentage of duplicate multicast packets may be observed being leaked to the to the egress interface. This is normal behavior. The re-route is triggered when traffic rate on the primary tunnel hits zero. Likewise, if no packets are detected on any of the lookup chips during the configured interval, the tunnel will go down.


rate—Specify a rate to represent the typical flow rate of aggregate multicast traffic from the provider tunnel (P tunnel). Aggregate multicast traffic from the P tunnel is monitored, and if it falls below the threshold set here a failover to the hot-root standby is triggered.

  • Range: 3 Mb through 100 Gb

revert-delay seconds—Use the specified interval to allow time for the network to converge when and if the original link comes back online. You can specify a time, in seconds, for the router to wait before updating its multicast routes. For example, if the original link goes down and triggers the switchover to an alternative link, and then the original link comes back up, the update of multicast routes reflecting the new path can be delayed to accommodate the time it may take to for the network to converge back on the original link.

  • Range: 0 through 20 seconds

Required Privilege Level

routing—To view this statement in the configuration.

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

Release Information

Statement introduced in Junos OS Release 16.1.