What is the prefix for the host address 2001:DB8:BC15:A:12AB::1/64?
- 2001:DB8:BC15
- 2001:DB8:BC15:A
- 2001:DB8:BC15:A:1
- 2001:DB8:BC15:A:12
Explanation: The network portion, or prefix, of an IPv6 address is identified through the prefix length. A /64 prefix length indicates that the first 64 bits of the IPv6 address is the network portion. Hence the prefix is 2001:DB8:BC15:A.