An IPv6 address is made up of bits that identify the network and host of a system. How many bits long is an IPv6 address in total, and how many bits identify the host portion?
1) 32 bits long in total, 8 bits identify the host portion
2) 64 bits long in total, 16 bits identify the host portion
3) 128 bits long in total, 64 bits identify the host portion
4) 256 bits long in total, 128 bits identify the host portion