Final answer:
In IPv6 addressing, a /32 global routing prefix and a /64 prefix are given. The number of bits allocated for the subnet ID is determined by subtracting the number of bits used for the global routing prefix from the total number of bits in the address.
Step-by-step explanation:
The subnet ID is the portion of an IPv6 address that identifies a specific network within the larger global routing prefix. In this case, we are given a /32 global routing prefix and a /64 prefix. The /32 prefix implies that the first 32 bits of the address are fixed and reserved for the global routing prefix. The /64 prefix implies that the next 64 bits are available for various subdivisions within the network. To determine how many bits are allocated for the subnet ID, we subtract the number of bits used for the global routing prefix from the total number of bits in the address. Therefore, the number of bits allocated for the subnet ID is 64 - 32 = 32 bits.