This parameter specifies a hex string which represents the subnet ID portion of the DUT’s LAN IPv6 prefix. This parameter is only used by CDRouter when the WAN mode is “6to4” or “6rd”, or when DHCPv6 prefix delegation is enabled.
In 6to4 terminology the subnet ID is referred to as the SLA ID and is fixed at 16 bits. As a result, this parameter should be four or less hex characters when 6to4 is used. In 6rd and DHCPv6-PD modes the subnet ID field can be variable length.