Cisco ASR 9000 Series Software Manual page 92

Multicast only fast reroute (MoFRR)
DETAILED STEPS
Command or Action
Step 1
configure
Step 2 router msdp
Example:
RP/0/RSP0/CPU0:router(config)# router msdp
Step 3
vrf vrf-name
Example:
RP/0/RSP0/CPU0:router(config-msdp) # vrf vrf1
Step 4 peer peer-address
Example:
RP/0/RSP0/CPU0:router(config-msdp) # peer 1.1.1.1
Step 5 commit
Multicast only fast reroute (MoFRR)
MoFRR allows fast reroute for multicast traffic on a multicast router. MoFRR minimizes packet loss in a
network when node or link failures occur(at the topology merge point). It works by making simple enhancements
to multicast routing protocols.
MoFRR involves transmitting a multicast join message from a receiver towards a source on a primary path
and transmitting a secondary multicast join message from the receiver towards the source on a backup path.
Data packets are received from the primary and secondary paths. The redundant packets are discarded at
topology merge points with the help of Reverse Path Forwarding (RPF) checks. When a failure is detected
on the primary path, the repair occurs locally by changing the interface on which packets are accepted to the
secondary interface, thus improving the convergence times in the event of a node or link failure on the primary
path.
MoFRR supports ECMP (Equal Cost Multipath) and non-ECMP topologies as well.
TI (Topology Independent) MoFRR is a multicast feature that performs fast convergence (Fast ReRoute) for
specified routes/flows when failure is detected on one of the paths between the router and the source.
Operating Modes of MoFRR
• Flow-based MoFRR— exposes the primary and secondary RPF interfaces to the forwarding plane, with
Cisco ASR 9000 Series Aggregation Services Router Multicast Configuration Guide, Release 5.1.x
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switchover occurring entirely at the hardware level.
Implementing Layer-3 Multicast Routing on Cisco IOS XR Software
Purpose
Enters MSDP configuration mode.
Enables VRF configuration for MSDP.
Configures the VRF MSDP peer .