What does this source address signify?

Frank installed Wireshark at all ingress points in the network. Looking at the logs he notices an odd packet source. The odd source has an address of 1080:0:FF:0:8:800:200C:4171 and is using port 21.

What does this source address signify?
A . This address means that the source is using an IPv6 address and is spoofed and signifies an IPv4 address of 127.0.0.1.
B . This source address is IPv6 and translates as 13.1.68.3
C . This source address signifies that the originator is using 802dot1x to try and penetrate into Frank’s network
D . This means that the source is using IPv4

View Answer

Answer: A

Explanation:

The address 1080:0:FF:0:8:800:200C:4171 is an IPv6 address. IPv6 addresses are 128-bit identifiers for interfaces and sets of interfaces. In this case, the address includes a block ::FFFF: (or 0:FF), which is a reserved subnet prefix to facilitate IPv4 to IPv6 migration. This is known as an IPv4-mapped IPv6 address. It is used to represent an IPv4 address in an IPv6 address format. The last 32 bits of the address represent an IPv4 address, which in this case corresponds to 127.0.0.1 – the loopback address in IPv4 used to establish an IP connection to the same machine or computer being used by the end-user.

Reference: The explanation is based on standard IPv6 addressing rules and the specific structure of IPv4-mapped IPv6 addresses. The information is consistent with the ECCouncil’s Network Defender (CND) course objectives regarding understanding and analyzing network protocols and addressing12.