Changing the SSM range group

Change the SSM range group to define the SSM range. The SSM range parameter extends the default SSM range of 232/8 to include an IP multicast address.

Before you begin

Before you disable or delete an ssm-map, always send IGMPv1 or IGMPv2 leave messages from hosts that operate in IGMPv1 or IGMPv2. If you do not perform this action, receiving and processing reports in SSM range on an IGMP interface enabled with IGMPv1 or IGMPv2 can lead to unexpected behavior.

About this task

Important

This procedure reinitializes PIM and temporarily stops all PIM traffic. For those multicast groups out of SSM range (for example, under PIM-SM behavior), it also causes a rendezvous point (RP) relearn delay of up to 60 seconds. This delay can be longer if the bootstrap router (BSR) is local.

You can configure IGMP on a VRF instance the same way you configure the Global Router except that you must use VRF Router Configuration mode.

Procedure

Enter Global Configuration mode:

enable

configure terminal
Disable PIM:

no ip pim enable

If you forget to disable PIM, the following error message appears:

Error: PIM is enabled in SSM mode, disable PIM
Delete each entry in the SSM channel table:

no ip igmp ssm-map [all] [{A.B.C.D} enable]

If you forget to delete the SSM channels, the following error message appears:

Error: SSM source group table not empty
Configure the new IP multicast group address:

ip igmp ssm group-range {A.B.C.D/X}

The following message appears:.

Warning: Changing the SSM range will cause all spb-multicast and spb-pim-gw enabled interfaces to be internally bounced. Do you wish to continue? (y/n) ? (y/n)?

Enter y to continue.
Enable PIM:

ip pim enable

Example

Configure the new IP multicast group address:

Switch:1(config)#ip igmp ssm group-range 232.0.0.0/16

WARNING: Changing the SSM range will cause all spb-multicast and spb-pim-gw enabled interfaces to be internally bounced. Do you wish to continue? (y/n) ? (y/n)? y

Variable definitions

Use the data in the following table to use the ip igmp ssm group-range and ip igmp ssm commands.


Variable	Value
{A.B.C.D/X}	Defines the SSM range. The SSM range parameter extends the default SSM range of 232/8 to include an IP multicast address. You can configure existing applications without having to change their group configurations. This parameter specifies an IP multicast address within the range of 224.0.0.0 and 239.255.255.255. The default is 232.0.0.0. The address mask is the IP address mask of the multicast group. The default is 255.0.0.0.