Restricting multicast traffic to RPTs
An alternate method to allowing the domain to use SPTs is to configure all of the routers in the domain to use only
RPTs. However, doing so can increase the traffic load in the network and cause delays in packet delivery.
Maintaining an active route for multicast group members
The edge router itself and any intervening routers on the active tree between the members (receivers) of a
multicast group and the DR for that group, send periodic joins. This keeps the active route available for as long as
there is a multicast receiver requesting the group. When a route times out or is pruned, the DR ceases to send
the requested group traffic on that route.
Border routers and multiple PIM-SM domains
Creating multiple domains enables a balancing of PIM-SM traffic within a network. Defining PIM-SM domain
boundaries requires the use of PIM border routers (PMBRs), and multiple PMBRs can be used between any two
domains.
NOTE:
The software described in this guide does not support PMBR operation for PIM-SM networks.
PIM-SM DT
PIM-SM and DT can be enabled within the same VLAN. Considered the following conditions when enabling PIM-
SM DT.
• To enable PIM-SM DT, configure PIM-SM and DT in the same VLAN.
• PIM-SM DT is not supported on a switch with v1 modules. The command
[no] allow-v1-modules
can be
used to disable any v1 modules.
• Since there can be multiple combinations of DT and PIM-SM configured in multiple VLANs, PIM-SM DT
feature should be enabled on the first combination of PIM-SM & DT in same VLAN and disabled when the last
such pair is un-configured.
For information about the
show distributed-trunking consistency-parameters global feature
pim-sm
and the
[no] allow-v1-module
commands, see the
Management and Configuration Guide
for your
switch.
PIM-SM router types
Within a PIM-SM domain, PIM-SM routers can be configured to fill one or more of the roles described in this
section.
DR:
A router performing this function forwards multicast traffic from a unicast source to the appropriate distribution
(rendezvous) point.
BSR:
A router elected to this function keeps all routers in a PIM-SM domain informed of the currently assigned RP
for each multicast group currently known in the domain.
RP:
A router elected as a RP for a multicast group receives requested multicast traffic from a DR and forwards it
toward the multicast receiver(s) requesting the traffic. See
on page 120.
118
Aruba 3810 / 5400R Multicast and Routing Guide for ArubaOS-
Switch 16.08
