21
Configuring static ports
If all the hosts attached to a port are interested in the multicast data addressed to a particular
multicast group or the multicast data that a particular multicast source sends to a particular group,
configure static (*, G) or (S, G) joining on that port, namely configure the port as a group-specific or
source-and-group-specific static member port.
Configure a port of a switch to be a static router port, through which the switch can forward all the
multicast traffic it received.
Follow these steps to configure static ports:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter Ethernet interface/Layer 2
aggregate interface view or port
group view
interface
interface-type
interface-number
Required
Use either approach
port-group
manual
port-group-name
Configure the port(s) as static
member port(s)
igmp-snooping static-group
group-address
[
source-ip
source-address
]
vlan
vlan-id
Required
No static member ports by default
Configure the port(s) as static
router port(s)
igmp-snooping
static-router-port
vlan
vlan-id
Required
No static router ports by default
NOTE:
•
A static (S, G) joining can take effect only if a valid multicast source address is specified and
IGMP snooping version 3 is running.
•
A static member port does not respond to queries from the IGMP querier; when static (*, G) or (S,
G) joining is enabled or disabled on a port, the port does not send an unsolicited IGMP report or
an IGMP leave message.
•
Static member ports and static router ports never age out. To remove such a port, you need to
use the corresponding
undo
command.
Configuring simulated joining
Generally, a host running IGMP responds to IGMP queries from the IGMP querier. If a host fails to
respond due to some reasons, the multicast router might deem that no member of this multicast
group exists on the network segment, and will remove the corresponding forwarding path.
To avoid this situation from happening, enable simulated joining on a port of the switch, namely
configure the port as a simulated member host for a multicast group. When receiving an IGMP query,
the simulated host gives a response. The switch can continue receiving multicast data.
A simulated host acts like a real host:
•
When a port is configured as a simulated member host, the switch sends an unsolicited IGMP
report through that port.
•
After a port is configured as a simulated member host, the switch responds to IGMP general
queries by sending IGMP reports through that port.
•
When the simulated joining function is disabled on a port, the switch sends an IGMP leave
message through that port.
Follow these steps to configure simulated joining: