Configuring Layer 2 Multicast Entry Limit in a VLAN Scenario

To limit the number of multicast groups in a VLAN scenario, configure Layer 2 multicast entry limit.

Context

On the network shown in Figure 1, PE1 is downlinked to a residential network VLAN 20 and uplinked to PE2 through an MPLS or a VPLS network to access the IPTV server. To save link bandwidth between PE1 and the residential network and ensure good subscribers' image experience, configure Layer 2 multicast entry limit for the VLAN on PE1. If some service providers group all the programs into one or more VLAN channels, Layer 2 multicast entry limit can also be configured to limit the multicast group number for each channel. In a VLAN scenario, Layer 2 multicast entry limit can be configured for a VLAN, GE 0/1/1, or a VLAN channel.

Figure 1 Configuring Layer 2 multicast entry limit in a VLAN scenario

On this network, PE1 is a Layer 2 device in a VLAN scenario. Configure Layer 2 multicast entry limit on PE1.

Layer 2 multicast entry limit cannot be performed for a protection VLAN.

Layer 2 multicast entry limit can be configured for a VLAN, an interface, or a VLAN on a specified interface. Perform the following configurations as needed.

Procedure

On PE1, configure Layer 2 multicast entry limit for a VLAN, an interface, or a VLAN on a specified interface.

Run system-view
The system view is displayed.

In a VLAN scenario, multicast group number limits can be configured based on different criteria. Choose any of or all the configurations as needed. For details, see Table 1.

**Table 1** Configuring Layer 2 multicast entry limit based on different criteria
Criteria	Multicast Group Number Limit
VLAN	Run the l2-multicast limit max-entry count vlan { { vlan-id1 [ to vlan-id2 ] } &<1-10> } [ except { acl-number \| acl-name acl-name } ] command to configure a multicast group number limit for a VLAN. except { acl-number \| acl-name acl-name } is used to prevent groups from being counted against the limit. The ACL specified in this command must have been configured.
Interface	Run the interface interface-type interface-number command to enter the view of an Ethernet, a GE, or an Eth-Trunk interface. Run the portswitch command to switch the interface to a Layer 2 interface. Run the l2-multicast limit max-entry count [ except { acl-number \| acl-name acl-name } ] command to configure a multicast group number limit for the interface. except { acl-number \| acl-name acl-name } is used to prevent groups from being counted against the limit. The ACL specified in this command must have been configured.
Interface + VLAN	Run the interface interface-type interface-number command to enter the view of an Ethernet, a GE, or an Eth-Trunk interface. Run the portswitch command to switch the interface to a Layer 2 interface. Run the l2-multicast limit max-entry count [ vlan { { vlan-id1 [ to vlan-id2 ] } &<1-10> } ] [ except { acl-number \| acl-name acl-name } ] command to configure a multicast group number limit for a specified VLAN on the interface. except { acl-number \| acl-name acl-name } is used to prevent groups from being counted against the limit. The ACL specified in this command must have been configured.