Avaya 8800 Planning And Engineering, Network Design page 206

Multicast network design
Static RP and auto-RP
Some legacy PIM-SMv1 networks may use the auto-RP protocol. Auto-RP is a Cisco proprietary
protocol that provides equivalent functionality to the standard Avaya Ethernet Routing Switch
8800/8600 PIM-SM RP and BSR. You can use the static RP feature to interoperate in this
environment. For example, in a mixed-vendor network, you can use auto-RP among routers that
support the protocol, while other routers use static RP. In such a network, ensure that the static RP
configuration mimics the information that is dynamically distributed to guarantee that multicast traffic
is delivered to all parts of the network.
In a mixed auto-RP and static RP network, ensure that the Ethernet Routing Switch 8800/8600 does
not serve as an RP because it does not support the auto-RP protocol. In this type of network, the
RP must support the auto-RP protocol.
Static RP and RP redundancy
You can provide RP redundancy through static RPs. To ensure consistency of RP selection,
implement the same static RP configuration on all PIM-SM routers in the network. In a mixed vendor
network, ensure that the same RP selection criteria is used among all routers. For example, to
select the active RP for each group address, the switch uses a hash algorithm defined in the PIM-
SMv2 standard. If a router from another vendor selects the active RP based on the lowest IP
address, then the inconsistency preventss the stream from being delivered to certain routers in the
network.
When a group address-to-RP discrepancy occurs among PIM-SM routers, network outages occur.
Routers that are unaware of the true RP cannot join the shared tree and cannot receive the
multicast stream.
Failure detection of the active RP is determined by the unicast routing table. As long as the RP is
considered reachable from a unicast routing perspective, the local router assumes that the RP is
fully functional and attempts to join the shared tree of that RP.
The following figure shows a hierarchical OSPF network where a receiver is located in a totally
stubby area. If RP B fails, PIM-SM router A does not switch over to RP C because the injected
default route in the unicast routing table indicates that RP B is still reachable.
June 2016 Planning and Engineering — Network Design
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