Circuitless Ip For Pim-Sm; Pim-Sm And Static Rp - Avaya 8800 Planning And Engineering, Network Design

If you cannot disable DVMRP or the streams, lower the DVMRP timers for faster convergence. Then
DVMRP learns its routes before PIM learns the new unicast routes and reroutes the stream.
If DVMRP and unicast routes diverge while traffic flows, the same problem may occur. As a result,
for safe MBR network operation, Avaya recommends that you use the simple design proposed in
PIM-SM to DVMRP connection: MBR.
MBR and path cost considerations
When using the MBR to connect PIM-SM domains to DVMRP domains, ensure that the unicast path
cost metric is not greater than 32, or issues may occur in the network. The DVMRP maximum metric
value is 32. On the MBR, DVMRP obtains metric information for the PIM domain routes from unicast
protocols. If DVMRP finds a route with a metric higher than 32 on the MBR, this route is considered
to be unreachable. The reverse path check (RPF) check fails and data is not forwarded.
To avoid this issue, make sure that your unicast routes do not have a metric higher than 32,
especially when using OSPF for routing. OSPF can have reachable routes with metrics exceeding
32.

Circuitless IP for PIM-SM

Use circuitless IP (CLIP) to configure a resilient RP and BSR for a PIM network. When you
configure an RP or BSR on a regular interface, if it becomes nonoperational, the RP and BSR also
become nonoperational. This results in the election of other redundant RPs and BSRs, if any, and
may disrupt IP multicast traffic flow in the network. As a sound practice for multicast networks
design, always configure the RP and BSR on a circuitless IP interface to prevent a single interface
failure from causing these entities to fail.
Avaya also recommends that you configure redundant RPs and BSRs on different switches and that
these entities be on CLIP interfaces. For the successful setup of multicast streams, ensure that a
unicast route to all CLIP interfaces from all locations in the network exists. A unicast route is
mandatory because, for proper RP learning and stream setup on the shared RP tree, every switch in
the network needs to reach the RP and BSR. PIM-SM circuitless IP interfaces can only be utilized
for RP and BSR configurations, and are not intended for other purposes.

PIM-SM and static RP

Use static RP to provide security, interoperability, and/or redundancy for PIM-SM multicast
networks. In some networks, the administrative ease derived from using dynamic RP assignment
may not be worth the security risks involved. For example, if an unauthorized user connects a PIM-
SM router that advertises itself as a candidate RP (CRP or cand-RP), it may possibly take over new
multicast streams that would otherwise be distributed through an authorized RP. If security is
important, static RP assignment may be preferable.
You can use the static RP feature in a PIM environment with devices that run legacy PIM-SMv1 and
auto-RP (a proprietary protocol that the Avaya Ethernet Routing Switch 8800/8600 does not
support). For faster convergence, you can also use static RP in a PIM-SMv2 environment. If static
RP is configured with PIM-SMv2, the BSR is not active.
June 2016
Protocol Independent Multicast-Sparse Mode guidelines
Planning and Engineering — Network Design
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