Igmp Snooping Querier; Mld Snooping; Multicast Vlan Registration; Layer 3 Multicast Features - Dell PowerConnect 7048P Manual

Powerconnect 7000 series stackable layer 2 and 3 switches

Hide thumbs Also See for PowerConnect 7048P:

Table of Contents

IGMP Snooping Querier

When Protocol Independent Multicast (PIM) and IGMP are enabled in a

network with IP multicast routing, the IP multicast router acts as the IGMP

querier. However, if the IP-multicast traffic in a VLAN needs to be Layer 2

switched only, an IP-multicast router is not required. The IGMP Snooping

Querier can perform the IGMP snooping functions on the VLAN.

In IPv4, Layer 2 switches can use IGMP Snooping to limit the flooding of

multicast traffic by dynamically configuring Layer 2 interfaces so that

multicast traffic is forwarded to only those interfaces associated with IP

multicast address.

In IPv6, MLD snooping performs a similar function. With MLD snooping,

IPv6 multicast data is selectively forwarded to a list of ports intended to

receive the data (instead of being flooded to all of the ports in a VLAN). This

list is constructed by snooping IPv6 multicast control packets.

The Multicast VLAN Registration (MVR) protocol, like IGMP Snooping,

allows a Layer 2 switch to listen to IGMP frames and forward the multicast

traffic only to the receivers that request it. Unlike IGMP Snooping, MVR

allows the switch to listen across different VLANs. MVR uses a dedicated

VLAN, which is called the multicast VLAN, to forward multicast traffic over

the Layer 2 network to the various VLANs that have multicast receivers as

For information about configuring L3 multicast features, see "Managing IPv4

and IPv6 Multicast" on page 1137.

Distance Vector Multicast Routing Protocol (DVMRP) exchanges probe

packets with all DVMRP-enabled routers, establishing two way neighboring

relationships and building a neighbor table. It exchanges report packets and

creates a unicast topology table, which is used to build the multicast routing

table. This multicast route table is then used to route the multicast packets.

Switch Features