33
Step Command
Remarks
3.
Enable multicast group
replacement.
igmp-snooping
overflow-replace
[
vlan
vlan-list
]
Disabled by default.
Setting the 802.1p precedence for IGMP messages
You can change the 802.1p precedence of IGMP messages so that they can be assigned higher
forwarding priority when congestion occurs on their outgoing ports.
Setting the 802.1p precedence for IGMP messages globally
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter IGMP-snooping view.
igmp-snooping
N/A
3.
Set the 802.1p precedence
for IGMP messages.
dot1p-priority
priority-number
The default 802.1p precedence
for IGMP messages is 0.
NOTE:
The global configuration takes effect for all VLANs.
Setting the 802.1p precedence for IGMP messages in a VLAN
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter VLAN view.
vlan
vlan-id
N/A
3.
Set the 802.1p precedence
for IGMP messages in the
VLAN.
igmp-snooping dot1p-priority
priority-number
The default 802.1p precedence
for IGMP messages is 0.
Configuring a multicast user control policy
Multicast user control policies are configured on access switches to allow only authorized users to
receive requested multicast traffic data. This helps restrict users from ordering certain
multicast-on-demand programs.
A multicast user control policy is functionally similar to a multicast group filter. A control policy can
control both multicast joining and leaving of users based on authentication and authorization.
However, multicast group filter is configured on a port to control only multicast joining but not leaving
of users without authentication or authorization.
In practice, a device first needs to perform authentication (for example, 802.1X authentication) for
the connected hosts through a RADIUS server. Then, the device uses the configured multicast user
control policy to perform multicast access control for authenticated users as follows:
•
After receiving an IGMP report from a host, the access switch matches the multicast group
address and multicast source address carried in the report against the configured policies. If a
match is found, the host is allowed to join the multicast group. Otherwise, the join report is
dropped by the access switch.
