ssm-mapping (IGMP)

Function

The ssm-mapping command configures an SSM mapping rule to map a multicast source to a group address.

The undo ssm-mapping command deletes an SSM mapping rule.

By default, no SSM mapping rule is configured.

Format

ssm-mapping group-address { group-mask | group-mask-length } source-address

undo ssm-mapping { group-address { group-mask | group-mask-length } [ source-address ] | static all }

Parameters

Parameter	Description	Value
group-address	Specifies a multicast group address.	The value ranges from 224.0.1.0 to 239.255.255.255, in dotted decimal notation.
group-mask	Specifies the mask of a multicast group address.	The mask is in dotted decimal notation.
group-mask-length	Specifies the mask length of a multicast group address.	The value is an integer that ranges from 4 to 32.
source-address	Specifies a multicast source address.	The address is in dotted decimal notation.
static all	Deletes all the configured static SSM mapping entries.	-

Views

IGMP view of the public network instance, IGMP view of a VPN instance

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

Hosts that support only IGMPv1 and IGMPv2 cannot join SSM groups. To enable multicast devices to provide the SSM service for these hosts, configure SSM mapping on the multicast devices. An SSM mapping entry maps a multicast source to a multicast group. After SSM mapping entries are configured on a multicast device, the device can convert (*, G) information in Report messages of IGMPv1 and IGMPv2 to (S, G) information.

The default range of SSM group addresses is 232.0.0.0 to 232.255.255.255. You can use the ssm-policy command to change the address range. All multicast groups out of this range are ASM groups.

The configured SSM mapping entries take effect only after the igmp ssm-mapping enable command is run on the interface.

Prerequisites

IP multicast routing has been enabled using the multicast routing-enable command.

Precautions

You can configure multiple static SSM mapping entries by running this command several times.
To delete an SSM mapping entry, run the undo ssm-mapping group-address { group-mask | group-mask-length } source-address command. The undo ssm-mapping static all command deletes all the SSM mapping entries. Do not use this command unless necessary.

Example

# In the public network instance, configure an SSM mapping entry to map multicast source address 10.8.8.8 to group address 225.5.5.5/32.

<HUAWEI> system-view
[HUAWEI] multicast routing-enable
[HUAWEI] igmp
[HUAWEI-igmp] ssm-mapping 225.5.5.5 32 10.8.8.8