Multicast Routing - Edge-Core ECS4620-28T Quick Start Manual

20
Overview

Multicast Routing

This chapter describes the following multicast routing topics:
◆
Enabling Multicast Routing Globally
multicast routing.
◆
Displaying the Multicast Routing Table
routing table.
◆
Configuring PIM for IPv4
IPv4.
◆
Configuring PIMv6 for IPv6
(Version 6) for IPv6.
This router can route multicast traffic to different subnetworks using Protocol-
Independent Multicasting - Dense Mode or Sparse Mode (PIM-DM or PIM-SM) for
IPv4, as well as PIM-DM for IPv6. PIM for IPv4 (also called PIMv4 in this manual) relies
on messages sent from IGMP-enabled Layer 2 switches and hosts to determine
when hosts want to join or leave multicast groups. PIM for IPv6 (also called PIMv6 in
this manual) uses the Multicast Listener Discovery (MLDv1) protocol which is the
IPv6 equivalent to IGMPv2. PIM-DM is designed for networks where the probability
of multicast group members is high, such as a local network. PIM-SM is designed for
networks where the probability of multicast group members is low, such as the
Internet.
Also, note that if PIM is not enabled on this router or another multicast routing
protocol is used on the network, the switch ports attached to a multicast router can
be manually configured to forward multicast traffic (see
Interfaces for a Multicast Router" on page
Configuring PIM-DM
PIM-DM floods multicast traffic downstream, and calculates the shortest-path,
source-rooted delivery tree between each source and destination host group.
Other multicast routing protocols, such as DVMRP, build their own source-rooted
multicast delivery tree (i.e., a separate routing table) that allows it to prevent
looping and determine the shortest path to the source of the multicast traffic.
PIM-DM also builds a source-rooted multicast delivery tree for each multicast
source, but uses information from the router's unicast routing table, instead of
– Describes how to globally enable
– Describes how to display the multicast
– Describes how to configure PIM-DM and PIM-SM for
– Describes how to configure PIM-DM and PIM-SM
546).
– 751 –
"Specifying Static