What is the host identifier of a device assigned the IPv6 address 2001:0db8:cafe:4500:1000:00d8:0058:00ab/64?

In an IPv6 address, the structure consists of two main parts: the network identifier and the host identifier. For an address with a subnet mask of /64, the first 64 bits represent the network portion, while the remaining 64 bits represent the host portion.

In the provided IPv6 address, 2001:0db8:cafe:4500:1000:00d8:0058:00ab, the breakdown is as follows:

• The first half (2001:0db8:cafe:4500) represents the network identifier.

• The second half (1000:00d8:0058:00ab) represents the host identifier.

Considering the /64 subnet mask, the correct host identifier is thus comprised of the last 64 bits, which corresponds to 1000:00d8:0058:00ab. This part uniquely identifies the device within that specific network.

Therefore, the correct identification of the host portion of the IPv6 address is indeed 1000:00d8:0058:00ab.