The Basic Mapping Rule’s Rule IPv6 prefix. See RFC 7599.
When using LW4o6, this testvar should be set to the IPv6 prefix used by the lwB4 to construct its source address. The value of this testvar is also used as the lwB4’s IPv6 binding prefix advertised by CDRouter in the OPTION_S46_V4V6BIND DHCPv6 option if mapEnableDhcpv6Options is enabled. See RFC’s 7596 and 7598.
This testvar was added in CDRouter 10.2