ssm-mapping query dns policy

Function

The ssm-mapping query dns policy command enables DNS-based SSM mapping.

The undo ssm-mapping query dns policy command disables DNS-based SSM mapping.

By default, DNS-based SSM mapping is disabled.

Format

ssm-mapping query dns policy { acl-number-value | acl-name acl-name-value }

undo ssm-mapping query dns policy { acl-number-value | acl-name acl-name-value }

Parameters

Parameter	Description	Value
acl-number-value	Specifies the number of a basic ACL.	The value is an integer ranging from 2000 to 2999.
acl-name acl-name-value	Specifies the name of the ACL.	The value is a string of 1 to 64 case-sensitive characters without spaces. The value must start with a letter (a to z or A to Z, case sensitive).

Parameter

Description

Value

acl-number-value

Specifies the number of a basic ACL.

The value is an integer ranging from 2000 to 2999.

acl-name acl-name-value

Specifies the name of the ACL.

The value is a string of 1 to 64 case-sensitive characters without spaces. The value must start with a letter (a to z or A to Z, case sensitive).

Views

IGMP view, VPN instance IGMP view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
igmp	write

Usage Guidelines

Usage Scenario

The static SSM mapping function requires the configuration of multicast source-group mappings on the multicast device that runs IGMPv3, so that the device can provide the SSM service for users using a lower IGMP version. However, this mode brings huge configuration workloads and cannot be flexibly changed.

To solve this problem, you can run the ssm-mapping query dns command to enable the DNS-based SSM mapping function so that the multicast device can provide the SSM service for users through SSM mappings provided by a DNS server.

Prerequisites

The igmp command has been used.

Example

# In the public network instance, enable DNS-based SSM mapping.

<HUAWEI> system-view
[~HUAWEI] acl 2000
[~HUAWEI-acl4-basic-2000] quit
[*HUAWEI] multicast routing-enable
[*HUAWEI] igmp
[*HUAWEI-igmp] ssm-mapping query dns policy acl 2000