200
2
300
3
Figure 4: Example of unknown multicast traffic not flooding out ports connected to queriers in separate VLANs
To display the status of IGMP multicast filtering use the show
ip igmp
command. If the IGMP Filter Unknown
Multicast setting is different from the IGMP Filter Unknown Multicast status, a reboot is required to activate the
desired setting. This setting will then be reflected in the status.
IGMP unknown multicast filter setting being enabled but not yet activated
switch(config)# show igmp filter-unknown-mcast
IGMP Filter Unknown Multicast: Enabled
IGMP Filter Unknown Multicast Status: Disabled
To display information about IGMP multicast filtering by interface, use the
show ip igmp
command.
IGMP proxy forwarding
When a network has a border router connecting a PIM-SM domain to a PIM-DM domain, the routers that are
completely within the PIM-DM domain have no way to discover multicast flows in the PIM-SM domain. When an
IGMP join occurs on a router entirely within the PIM-DM domain for a flow that originates within the PIM-SM
domain, it is never forwarded to the PIM-SM domain.
The IGMP proxy is a way to propagate IGMP joins across router boundaries. The proxy triggers the boundary
router connected to a PIM-SM domain to query for multicast flows and forward them to the PIM-DM domain.
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Aruba 3810 / 5400R Multicast and Routing Guide for ArubaOS-
Switch 16.08