System information

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Multicast Filtering
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Displaying Interfaces Attached to a Multicast Router
Multicast routers that are attached to ports on the switch use information obtained
from IGMP, along with a multicast routing protocol such as DVMRP, to support IP
multicasting across the Internet. These routers may be dynamically discovered by
the switch or statically assigned to an interface on the switch.
You can use the Multicast Router Port Information page to display the ports on this
switch attached to a neighboring multicast router/switch for each VLAN ID.
Command Attributes
• VLAN ID – ID of configured VLAN (1-4094).
• Multicast Router List – Multicast routers dynamically discovered by this switch or
those that are statically assigned to an interface on this switch.
Web – Click IGMP, Multicast Router Port Information. Select the required VLAN ID
from the scroll-down list to display the associated multicast routers.
Figure 2-54. Displaying Multicast Router Port Information
CLI – This example shows that Port 11 has been statically configured as a port
attached to a multicast router.
Specifying Interfaces Attached to a Multicast Router
Depending on your network connections, IGMP snooping may not always be able to
locate the IGMP querier. Therefore, if the IGMP querier is a known multicast router/
switch connected over the network to an interface (port or trunk) on your switch, you
can manually configure that interface to join all the current multicast groups. This
Console#show ip igmp snooping mrouter vlan 1 3-110
VLAN M'cast Router Port Type
---- ------------------ -------
1 Eth 1/11 Static
Console#