Define the ISATAP address format.
The ISATAP address format is created from the concatenation of a prefix and the interface ID in ISATAP format. The link-local prefix of an ISATAP address is FE80::/10. One aggregatable global unicast prefix must be dedicated to the ISATAP operation within a domain (all ISATAP devices must use the same prefix). The interface ID (low-order 64-bit) in the ISATAP format is made by appending the IPv4 address of the ISATAP host or ISATAP router to the hexadecimal value 0000:5EFE. The final representation of an ISATAP address is prefix:0000:5EFE:ipv4-address.