What is the typical size of the global routing prefix in an IPv6 global unicast address?

The typical size of the global routing prefix in an IPv6 global unicast address is 48 bits. In IPv6 addressing, global unicast addresses are structured in a way that enhances efficient routing on the Internet. The address format consists of a global routing prefix that identifies a specific network and typically occupies the first 48 bits of the address.

This 48-bit prefix is assigned by a registry (such as IANA or a regional Internet registry) to identify large blocks of addresses allocated to specific organizations or ISPs. Following the global routing prefix, the address usually incorporates a 16-bit subnet identifier, which allows organizations to create several subnets within their allocated address space. Finally, the remaining 64 bits of the address are reserved for the interface identifier, typically derived from the MAC address of the host or generated using other methods.

Understanding this structure helps in effectively routing and managing IPv6 addresses, ensuring communication across diverse networks.