Owner's Manual

750 | Chapter 27. Multicast Routing and Switching
NETGEAR 8800 User Manual
1. Configure MVR on McastVlan.
2. Configure an IP address and enable IGMP and IGMP snooping on the subscriber VLANs
(by default IGMP and IGMP snooping are enabled on NETGEAR switches).
3. For all the multicast streams (IPTV channels), configure static IGMP snooping membership
on the router on McastVlan.
4. Enable MVR on the switches in the network.
Note: MVR works best with IGMPv1 and IGMPv2. NETGEAR
recommends that you do not use MVR with IGMPv3.
The strategy above conserves bandwidth in the core and does not require running PIM on the
subscriber switches.
In this topology, a host (for example, a cable box or desktop PC) joins a channel through an
IGMP join message. Switch1 snoops this message and adds the virtual port to the
corresponding cache's egress list. This is possible because an MVR enabled VLAN can leak
traffic to any other VLAN. When the user switches to another channel, the host sends an
IGMP leave for the old channel and a join for the new channel. The corresponding virtual port
is removed from the cache for the old channel and is added to the cache for the new channel.
As discussed in Static and Dynamic MVR on page 750, McastVlan also proxies IGMP joins
learned on other VLANs to the router. On an MVR network it is not mandatory to have a
router to serve the multicast stream. All that is required is to have a designated IGMP querier
on McastVlan. The IPTV server can also be directly connected to McastVlan.
Static and Dynamic MVR
This section presents the following topics:
• Static MVR on page 750
• Dynamic MVR on page 751
• Configuring Static and Dynamic MVR on page 751
Static MVR
In a typical IPTV network, there are several high demand basic channels. At any instant there
is at least one viewer for each of these channels (streams), and they should always be
available at the core. When a user requests one of these channels, it is quickly pulled locally
from the multicast VLAN. These streams are always available on the core multicast VLAN
through static configuration on the streaming router. For those channels, the Layer
2 switch
does not send any IGMP join messages towards the IGMP querier. These groups must be
statically configured on the streaming router so that these streams are always available on
the ring. For example, on an NETGEAR router, you can use the following command:
configure igmp snooping {vlan} <vlanname> ports <portlist> add static group <ip
address>