This parameter specifies the number of high-order bits that are identical across all IPv4 addresses within a 6rd domain. If the IPv4 mask length is 0, the DUT’s entire WAN IPv4 address is used to create the 6rd delegated prefix. If the DUT’s 6rd mask length is 8, only the lowest order 24 bits of the DUT’s WAN IPv4 address are used to create the 6rd prefix. The IPv4 mask length must be an integer value between 0 and 32.
Some 6rd configuration examples:
Private WAN IPv4 Address
WAN IPv4 Address: 192.168.200.2 6rd Prefix: 2010:1234:: 6rd Prefix Length: 32 6rd IPv4 Mask Length: 8 6rd Delegated Prefix: 2010:1234:A8C8:0200:/56
Public WAN IPv4 Address
WAN IPv4 Address: 188.8.131.52 6rd Prefix: 2010:: 6rd Prefix Length: 16 6rd IPv4 Mask Length: 0 6rd Delegated Prefix: 2010:0C0C:0C02::/48
Note that stateless address autoconfiguration (autoconf) requires an IPv6 prefix less than or equal to 64 bits. The test run will be aborted if autoconf is used on the LAN and the DUT provides a 6rd prefix greater than 64 bits in length.