Binary Pattern of Unique IPv6 Unique Local Address

B

A IPv6 Unique Local Address is an IPv6 address in the block FC00::/7, which means that IPv6 Unique Local addresses begin with 7 bits with exact binary pattern as 1111 110 -> Answer B is correct.

Note: IPv6 Unique Local Address is the approximate IPv6 counterpart of the IPv4 private address. It is not routable on the global Internet.

The unique local address (ULA) is an IPv6 address that is reserved for private use within a particular organization or site, just like the private IPv4 address space of 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. The ULA prefix is fc00::/7, which means that the first seven bits of the address start with the binary pattern "1111110".

To create a unique local address, you need to generate a random 40-bit global ID and then insert the ULA prefix. This gives you a 48-bit address, which you can then expand to 64 bits by adding the network prefix and interface identifier. The resulting address is guaranteed to be globally unique within the organization, while still being private and not visible on the public internet.

Therefore, the binary pattern of the ULA prefix is "1111110", which corresponds to option D, "11111101".