Pim-Sm; Dvmrp; Ipms And Link Aggregation; Igmp Version 3 - Alcatel OmniSwitch 6800 Series Network Configuration Manual

Configuring IP Multicast Switching

PIM-SM

Protocol-Independent Multicast (PIM) is an IP multicast routing protocol that uses routing information
provided by unicast routing protocols such as RIP and OSPF. Sparse mode PIM (PIM-SM) contrasts with
flood-and-prune dense mode multicast protocols such as DVMRP and PIM Dense Mode (PIM-DM) in
that multicast forwarding in PIM-SM is initiated only via specific requests. Downstream routers must
explicitly join PIM-SM distribution trees in order to receive multicast streams on behalf of directly-
connected receivers or other downstream PIM-SM routers. This paradigm of receiver-initiated forwarding
makes PIM-SM ideal for network environments where receiver groups are thinly populated and band-
width conservation is a concern, such as in Wide Area Networks (WANs).

DVMRP

Distance Vector Multicast Routing Protocol (DVMRP) is a distributed multicast routing protocol that
dynamically generates per-source delivery trees based upon routing exchanges. When a multicast source
begins to transmit, the multicast data is flooded down the delivery tree to all points in the network.
DVMRP then prunes (i.e., removes branches from) the delivery tree where the traffic is unwanted. This is
in contrast to PIM-SM, which uses receiver-initiated (i.e., forward path) multicasting.

IPMS and Link Aggregation

When configuring IPMS and link aggregation on the same switch the following conditions should be kept
in mind:
When a port moves to a link aggregation group all IPMS configurations on the port will be lost.
•
When the last port in a link aggregation group moves out of the group all IPMS configuration on the
•
link aggregation group will be lost.

IGMP Version 3

IGMP is used by IPv4 systems (hosts and routers) to report their IP multicast group memberships to any
neighboring multicast routers. IGMP version 2 (IGMPv2) handles forwarding by IP multicast destination
address only. IGMP version 3 (IGMPv3) handles forwarding by source IP address and IP multicast desti-
nation address. OmniSwitch 6800 Series switches support IGMPv2 and IGMPv3.
Note. See "Configuring the IGMP Proxy Version" on page 23-8
version.
OmniSwitch 6800 Series Network Configuration Guide
for information on configuring the IGMP
November 2004
IPMS Overview
page 23-5