It's an IPv4-mapped IPv6 address. Just interpret the IPv4 address like it's the last 32 bits of the v6 address. In the example, 64:ff9b::103:307 is equivalent.

It's an IPv4-mapped IPv6 address. Just interpret the IPv4 address like it's the last 32 bits of the v6 address. In the example, 64:ff9b::103:307 is equivalent. A more complicated example might be akin to 64:ff9b::198.51.100.231, equivalent to 64:ff9b::c633:64e7.