Multicast Routing Commands - Alcatel-Lucent 060321-10, Rev. B Cli Reference Manual

This chapter describes multicast routing commands. Multicast routing is used in conjunction with
IP Multicast Switching (IPMS). IPMS can operate either with or without multicast routing. However,
for Multicast Routing to function, IPMS must be configured.
Multicast uses Class D IP addresses in the range 224.0.0.0 to 239.255.255.255. Addresses in the range
239.0.0.0 to 239.255.255.255 are reserved for boundaries, which are used to prevent multicast traffic from
being forwarded on a VLAN group or network.
IP multicast routing is a way of controlling multicast traffic across networks. The multicast router discov-
ers which networks want to receive multicast traffic by sending out Internet Group Management Protocol
(IGMP) queries and receiving IGMP reports from attached networks. The IGMP reports signal that users
want to join or leave a multicast group. If there is more than one multicast router in the network, the router
with the lowest IP address is elected the querier router, which is responsible for querying the subnetwork
for group members.
The current release also provides support for IPv6 multicast addresses. In the IPv6 addressing scheme,
multicast addresses begin with the prefix ff00::/8. Similar to IPv6 unicast addresses, IPv6 multicast
addresses also have different scopes depending on their prefix, though the range of possible scopes is
different.
Multicast Listener Discovery (MLD) is the protocol used by an IPv6 router to discover the nodes which
request multicast packets on its directly attached links and the multicast addresses that are of interest to
those neighboring nodes. MLD is derived from version 2 of IPv4's Internet Group Management Protocol,
IGMPv2. MLD uses ICMPv6 message types, rather than IGMP message types.
MIB information for the multicast routing commands is as follows:
Filename: AlcatelIND1Ipmrm.mib
Module: ALCATEL-IND1-IPMRM-MIB
Filename: AlcatelIND1IpMcastDraft.mib
Module: ALCATEL-IND1-IPMCAST-MIB
OmniSwitch CLI Reference Guide
24 Multicast Routing
March 2011
Commands
page 24-1