3Com 4800G Series, Configuration Manual

Page: 594 / 1246

594 C
HAPTER
43: MLD S
NOOPING
C
ONFIGURATION
Configuring Maximum
Multicast Groups that
that Can Be Joined on a
Port
By configuring the maximum number of IPv6 multicast groups that can be joined
on a port or a group of ports, you can limit the number of multicast programs
available to VOD users, thus to control the traffic on the port.
Follow these steps configure the maximum number of IPv6 multicast groups that
can be joined on a port or a group of ports:
n
■
When the number of IPv6 multicast groups that can be joined on a port
reaches the maximum number configured, the system deletes all the
forwarding entries persistent to that port from the MLD Snooping forwarding
table, and the hosts on this port need to join IPv6 multicast groups again.
■
If you have configured static or simulated joins on a port, however, when the
number of IPv6 multicast groups on the port exceeds the configured threshold,
the system deletes all the forwarding entries persistent to that port from the
MLD Snooping forwarding table and applies the static or simulated joins again,
until the number of IPv6 multicast groups joined by the port comes back within
the configured threshold.
Configuring IPv6
Multicast Group
Replacement
For some special reasons, the number of IPv6 multicast groups passing through a
switch or port may exceed the number configured for the switch or the port. In
addition, in some specific applications, an IPv6 multicast group newly joined on
the switch needs to replace an existing IPv6 multicast group automatically. A
typical example is “channel switching”, namely, by joining the new multicast, a
user automatically switches from the current IPv6 multicast group to the one.
To address this situation, you can enable the IPv6 multicast group replacement
function on the switch or certain ports. When the number of IPv6 multicast groups
a switch or a port has joined exceeds the limit.
■
If the IPv6 multicast group replacement is enabled, the newly joined IPv6
multicast group automatically replaces an existing IPv6 multicast group with
the lowest IPv6 address.
To do… Use the command… Remarks
Enter system view system-view -
Enter MLD Snooping view mld-snooping -
Enable MLD report
suppression report-aggregation Optional
Enabled by default
To do… Use the command… Remarks
Enter system view system-view -
Enter the
corresponding view Enter Ethernet
port view interface interface-type
interface-number
Use either command
Enter port
group view port-group { manual
port-group-name |
aggregation agg-id }
Configure the maximum number of
IPv6 multicast groups that can be
joined on a port mld-snooping
group-limit
limit [ vlan
vlan-list ]
Optional
The default is 512.