mld limit

Function

The mld limit command sets the maximum number of MLD group memberships that the current interface can maintain.

The undo mld limit command restores the maximum number of MLD group memberships that the current interface can maintain to the default value.

The following lists the maximum number of MLD group memberships that can be maintained on the current interface of each model by default:

S5720-LI, S5720S-LI: 496
S5730-SI, S5730S-EI, S6720-LI, S6720S-LI, S6720-SI, S6720S-SI: 512
S5731-S, S5731S-S, S5720I-SI, S5720S-SI, S5720-SI: 1024
S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735S-S, S5735-S-I: 1500
S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731S-H, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, S6730S-S: 2048
S6720S-EI, S6720-EI: 4096

Format

mld limit number [ except acl6-number ]

undo mld limit

Parameters

Parameter	Description	Value
number	Specifies the maximum number of MLD group memberships that can be maintained on the current interface.	The value is an integer that ranges from 1 to The maximum number of MLD group memberships that can be maintained on the current interface by default. NOTE: The value range of S5720-HI, S5730-HI, S5731-H, S5731S-H, S5732-H, S6720-HI, S6730S-H, and S6730-H are expanded after the high specification mode is configured for multicast forwarding using the set multicast forwarding-table super-mode command. The actual value range depends on the specification of the device.
except	Specifies the range of multicast groups that are not limited by the specified maximum number.	-
acl6-number	Specifies the basic or advanced ACL6.	The value is an integer. The number of the basic ACL6 ranges from 2000 to 2999. The basic ACL6 filters group addresses only, without distinguishing (*, G) entries and (S, G) entries. The number of the advanced ACL6 ranges from 3000 to 3999. The advanced ACL6 filters (S, G) entries of the interface only.

Views

GE interface view, XGE interface view, MultiGE interface view, 25GE interface view, 40GE interface view, 100GE interface view, Eth-Trunk interface view, VLANIF interface view, loopback interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When the number of MLD entries reaches the limit, the system does not create any MLD entries. To allow more new join requests, delete unnecessary entries or increase the limit. Alternatively, configure static multicast groups or source-group bindings on interfaces.

The number of MLD entries can be counted in the following methods:

Each (*, G) entry is counted as one entry.
Each (S, G) entry is counted as one entry.
Each (*, G) entry for SSM mapping is counted as one entry.

Prerequisites

Layer 3 IPv6 multicast has been enabled using the multicast ipv6 routing-enable command in the system view.

Precautions

If except is not set in the command, the maximum number of MLD entries corresponding to all the groups or source/groups is limited.

Before setting except, configure the associated ACL6. The interface then filters the received MLD Join messages according to the ACL6. The maximum number of entries corresponding to the multicast groups that match the ACL6 is not limited.

The mld limit command must be used with ACL6 configuration commands. When configuring ACL6 rules, note that:

In the basic ACL6 view, specify the source parameter in the rule (basic ACL6 view) command for setting the range of multicast groups whose MLD entries do not need to be limited.
In the advanced ACL6 view, specify the source parameter in the rule (advanced ACL6 view) command for setting the range of sources that are allowed to send multicast data to the multicast groups. Specify the destination parameter in the rule (advanced ACL6 view) command for setting the range of multicast groups whose MLD entries do not need to be limited.

The Named ACL and the advanced ACL can be configured based on the same rules, and can implement filtering of both source addresses and multicast group addresses. The time-range parameter takes effect in the rule command only for the Named ACL.

Example

# Set the maximum number of MLD entries that can be created on the VLANIF100 to 1024.

<HUAWEI> system-view
[HUAWEI] multicast ipv6 routing-enable
[HUAWEI] interface vlanif 100
[HUAWEI-Vlanif100] mld limit 1024

# Create the advanced ACL6 with the number being 3100; set the maximum number of MLD entries that can be created on VLANIF100 to 1024; allow the hosts to receive messages from the specific-source multicast group (FC00:0:0:2001::1, FF3E::1). That is, the specific-source multicast group (FC00:0:0:2001::1, FF3E::1) is not limited by the maximum number of MLD entries.

<HUAWEI> system-view
[HUAWEI] multicast ipv6 routing-enable
[HUAWEI] acl ipv6 3100
[HUAWEI-acl6-adv-3100] rule permit ipv6 source fc00:0:0:2001::1 64 destination ff3e::1 64
[HUAWEI-acl6-adv-3100] quit
[HUAWEI] interface vlanif 100
[HUAWEI-Vlanif100] mld limit 1024 except 3100

# Set the maximum number of MLD entries that can be created on the GE0/0/1 to 1024.

<HUAWEI> system-view
[HUAWEI] multicast ipv6 routing-enable
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] undo portswitch
[HUAWEI-GigabitEthernet0/0/1] mld limit 1024