Operation Manual – Multicast
H3C S3100 Series Ethernet Switches
Chapter 1 Multicast Overview
1-10
1.3.2 Multicast Protocols
Note:
z
Generally, we refer to IP multicast working at the network layer as Layer 3 multicast
and the corresponding multicast protocols as Layer 3 multicast protocols, which
include IGMP, PIM, and MSDP; we refer to IP multicast working at the data link layer
as Layer 2 multicast and the corresponding multicast protocols as Layer 2 multicast
protocols, which include IGMP Snooping.
z
This section provides only general descriptions about applications and functions of
the Layer 2 and Layer 3 multicast protocols in a network. For details about these
protocols, refer to the related chapters of this manual.
I. Layer 3 multicast protocols
Layer 3 multicast protocols include multicast group management protocols and
multicast routing protocols.
Figure 1-5
describes where these multicast protocols are in
a network.
AS 1
AS 2
Source
Receiver
Receiver
Receiver
PIM
PIM
MSDP
IGMP
IGMP
IGMP
Figure 1-5
Positions of Layer 3 multicast protocols
1)
Multicast management protocols
Typically, the Internet Group Management Protocol (IGMP) is used between hosts and
Layer 3 multicast devices directly connected with the hosts. These protocols define the
mechanism of establishing and maintaining group memberships between hosts and
Layer 3 multicast devices.