Cisco Nx-Os Pim And Pim6 - Cisco Nexus 7000 Series Configuration Manual

Cisco NX-OS PIM and PIM6

Figure 5: RPF Check Example
Cisco NX-OS PIM and PIM6
Cisco NX-OS supports multicasting with Protocol Independent Multicast (PIM) sparse mode. PIM is IP
routing protocol independent and can leverage whichever unicast routing protocols are used to populate the
unicast routing table. In PIM sparse mode, multicast traffic is sent only to locations of the network that
specifically request it. PIM dense mode is not supported by Cisco NX-OS.
Note In this publication, the term "PIM" is used for PIM sparse mode version 2.
To access multicast commands, you must enable the PIM or PIM6 feature. Multicast is enabled only after
you enable PIM or PIM6 on an interface of each router in a domain. You configure PIM for an IPv4 network
and PIM6 for an IPv6 network. By default, IGMP and MLD are running on the system.
PIM, which is used between multicast-capable routers, advertises group membership across a routing domain
by constructing multicast distribution trees. PIM builds shared distribution trees on which packets from
multiple sources are forwarded, as well as source distribution trees, on which packets from a single source
are forwarded.
The distribution trees change automatically to reflect the topology changes due to link or router failures. PIM
dynamically tracks both multicast-capable sources and receivers, although the source state is not created in
Bidir mode.
The router uses the unicast routing table and RPF routes for multicast to create multicast routing information.
In Bidir mode, additional routing information is created.
Note
In this publication, "PIM for IPv4" and "PIM6 for IPv6" refer to the Cisco NX-OS implementation of PIM
sparse mode. A PIM domain can include both an IPv4 and an IPv6 network.
The figure below shows two PIM domains in an IPv4 network.
Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide
8
Overview