Dell M6220 User Configuration Manual page 1233

Figure 43-45. Add SSM Range
3 Click the Add Default SSM Range check box to add the default SSM
Range. The default SSM Range is 232.0.0.0/8 for IPv4 multicast and
ff3x::/32 for IPv6 multicast.
4 Enter the SSM Group IP Address.
5 Enter the SSM Group Mask (IPv4) or SSM Prefix Length (IPv6).
6 Click Apply.
The new SSM Range is added, and the device is updated.
Managing IPv4 and IPv6 Multicast
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