For this next IPv6 addressing drill, you begin with a prefix configured on a router LAN interface using the ipv6 address prefix-id/64 eui-64 command. Your job: calculate the Global Unicast Addresses (GUA) and Link-Local Address (LLA) used on the interface using EUI-64 rules.

This post has both the questions and the answers – just click the items in the post to reveal.

IPv6 hosts and routers must use at least one Link-Local Addresses (LLA) on each interface. Originally, devices formed their LLAs using a standard 16-digit prefix (fe80:0000:0000:0000) along with a 16-digit interface ID (IID) formed from the interface MAC address using EUI-64 rules. Today, some devices use a randomization process to find the IID, but some still use EUI-64, including Cisco routers. So, you need to understand the EUI-64 process for LLAs.

When using the eui-64 keyword on the ipv6 address interface subcommand, Cisco routers calculate the IID (2^nd half) of a routable unicast address(es) using EUI-64 rules. In short, the configuration supplies the prefix (the first 16 digits), and the router calculates the IID using EUI-64 rules and the interface MAC address.

The following table lists a problem number, a GUA prefix, and a MAC address. From that data, calculate:

1. The expanded GUA, using EUI-64 rules
2. The abbreviated version of that same GUA
3. The expanded LLA, using EUI-64 rules
4. The abbreviated version of that same LLA

Question Set: