BEC 8920AC User Manual page 136

 Automatically: 6rd parameters will be configured by the system.
 Manually: Fill out the following 6rd parameters:
V4 Common Bit Length: Specify the length of IPv4 address carried in IPv6 prefix.
For example, 0 means to carry all the 32 bits of IPv4 address while 8 carries 24 bits of the IPv4
address.
6rd Prefix with Prefix Length: Enter the 6rd prefix and prefix length you uniquely designate to
6rd by the ISP (The 6rd prefix and prefix length are to replace the standard 6to4 prefix 2002::/16
by an IPv6 prefix that belongs to the ISP-assigned.)
Border Relay IPv4 Address: The IPv4 address of the border relay. The relay is to un-wrap
capsulated IPv4 packets into IPv6 packets and send them to the IPv6 network.
BEC 8920AC User Manual
Configuring Your Router
IP Tunnel – IPv6 in IPv4 (6RD)
125