Enabling Multicast Group Replacement; Setting The 802.1P Precedence For Igmp Messages - HP 6125G Configuration Manual

Enabling multicast group replacement

For various reasons, the number of multicast groups that the switch or a port joins might exceed the upper
limit. In addition, in some specific applications, a multicast group that the switch newly joins must replace
an existing multicast group automatically. A typical example is channel switching. To view a new channel,
a user switches from the current multicast group to the new one.
To realize such requirements, you can enable the multicast group replacement function on the switch or
on a certain port. When the number of multicast groups that the switch or on the port has joined reaches
the limit, one of the following occurs:
If the multicast group replacement feature is disabled, new IGMP reports are automatically
•
discarded.
If the multicast group replacement feature is enabled, the multicast group that the switch or a port
•
newly joins automatically replaces an existing multicast group that has the lowest address.
IMPORTANT:
In the configuration, be sure to configure the maximum number of multicast groups allowed on a port (see
"Setting the maximum number of multicast groups that a port can
replacement. Otherwise, the multicast group replacement functionality will not take effect.
Enabling multicast group replacement globally
Step
1. Enter system view.
2. Enter IGMP-snooping view.
3. Enable multicast group
replacement.
Enabling multicast group replacement on a port
Step
1. Enter system view.
2. Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view.
3. Enable multicast group
replacement.

Setting the 802.1p precedence for IGMP messages

You can change the 802.1p precedence for IGMP messages so that they can be assigned higher
forwarding priority when congestion occurs on their outgoing ports.
Command
system-view
igmp-snooping
overflow-replace [ vlan vlan-list ]
Command
system-view
interface interface-type
interface-number
igmp-snooping overflow-replace
[ vlan vlan-list ]
30
join") before enabling multicast group
Remarks
N/A
N/A
Disabled by default
Remarks
N/A
Use either command.
Disabled by default.