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Implementing Multicast Routing on Cisco IOS XR Software
Command or Action
Step 7
end route-policy
Example:
RP/0/RP0/CPU0:router(config-rpl) #
Step 8
router pim address-family[ipv4 |ipv6]
Example:
RP/0/RP0/CPU0:router(config) # router pim address-family
ipv4
Step 9
rpf topology route-policypolicy-namepim policy
Example:
RP/0/RP0/CPU0:router(config) # rpf topology route-policy
r1 pim policy
Point-to-Multipoint Traffic Engineering Label-Switched
Multicast
IP multicast was traditionally used for IPTV broadcasting and content delivery services. MPLS-TE (traffic
engineering) is fast replacing the IP multicast technique because of the various advantages of MPLS-TE, such
as:
• Fast re-routing and restoration in case of link/ node failure
• Bandwidth guarantee
• Explicit path setting along with off-line computation
MPLS supports point-to-point path. However, in order to use MPLS for multicast service, MPLS has to be
extended to handle point-to-multipoint paths. A reliable solution to signal Point-to-Multipoint (P2MP) label
switched paths(LSP) is the Point-to-Multipoint TE LSP. This solution uses the Resource Reservation Protocol-
Traffic Engineering (RSVP-TE) extension as the signaling protocol for establishing P2MP TE LSPs.
Point to Multipoint LSP(P2MP)
P2MP LSP is unidirectional. In case of native IP multicast, the multicast forwarding always has to perform
an acceptance check. This check ensures all multicast packets undergo a RPF check to ensure that the packets
have arrived on the correct interface in the direction of the source. However, the acceptance check with MPLS
forwarding may be different in case of an unicast or upstream label.
Depending on the multicast signaling protocol, the labeled packet may require an additional L3 lookup at the
P and PE routers in order to forward the multicast packet to the physical interfaces according to multicast
routing. In this case, the incoming P2MP LSP as the incoming interface for the received multicast packet must
Point-to-Multipoint Traffic Engineering Label-Switched Multicast
end route-policy r1
Cisco IOS XR Multicast Configuration Guide for the Cisco CRS Router, Release 5.2.x
Purpose
Ends the route policy.
Enters the PIM address-family configuration
sub-mode.
Selects the RPF topology for the configured
route-policy.
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