H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 65)

56
When you configure this maximum number, if the number of IPv6 multicast groups the port has joined
exceeds the configured maximum value, the system deletes all the forwarding entries for the port from the
MLD snooping forwarding table, and the hosts on this port join IPv6 multicast groups again until the
number of IPv6 multicast groups that the port joins reaches the maximum value. When the port joins an
IPv6 multicast group, if the port has been configured as a static member port, the system applies the
configurations to the port again. If you have configured simulated joining on the port, the system
establishes corresponding forwarding entry for the port after receiving a report from the simulated
member host.
To configure the maximum number of IPv6 multicast groups that a port can join:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Layer 2 Ethernet
interface view, Layer 2
aggregate interface view, or
port group view.
• Enter Layer 2 Ethernet interface
view or Layer 2 aggregate
interface view:
interface interface-type
interface-number
• Enter port group view:
port-group manual
port-group-name
Use either approach.
3. Configure the maximum
number of IPv6 multicast
groups that a port can join.
mld-snooping group-limit limit
[ vlan vlan-list ]
256 by default.
Configuring IPv6 multicast group replacement
Sometimes, the number of IPv6 multicast groups that the access controller or a port joins might exceed
the upper limit. In addition, in some specific applications, an IPv6 multicast group that the access
controller newly joins must replace an existing IPv6 multicast group automatically. A typical example is
channel switching: To view a new channel, a user switches from the current IPv6 multicast group to the
new one.
To address this situation, enable the IPv6 multicast group replacement function on the access controller
or a certain port. When the number of IPv6 multicast groups the access controller or a port has joined
exceeds the limit, one of the following occurs:
• If the IPv6 multicast group replacement is not enabled, new MLD reports are automatically
discarded.
• If the IPv6 multicast group replacement is enabled, the IPv6 multicast group that the access
controller or the port newly joins automatically replaces an existing IPv6 multicast group that has the
lowest IPv6 address.
IMPORTANT:
Be sure to configure the maximum number of IPv6 multicast groups that a port can join (see " Setting the
maximum number of multicast groups that a port can join ") before enabling IPv6 multicast group
replacement. Otherwise, the IPv6 multicast group replacement functionality does not take effect.