IPv6 Icky EUI-64 Drill 1 – Answers

certskills
By certskills April 1, 2017 09:50

Short and icky sweet: this post lists answers for the icky EUI-64 drill 1 for #ICND2 and #CCNA. The problems require you to find the IPv6 address a host or router would use, given a prefix, MAC address, and assuming they use stateless auto-configuration. This post lists the answers.

Related links:

The Answers

Table 1 lists the original problems. Table 2 then lists the unicast IPv6 addresses as calculated with EUI-64, before abbreviation, with table 3 listing the same addresses in abbreviated form as requested. Table 4 then lists the solicited node multicast address just for fun. Also, for a quick review, note that the rules for creating the second half of the unicast address using SLAAC is as follows: split the MAC, insert FFFE, and invert the 7th bit. Figure 1 summarizes the process.

Figure 1: EUI-64 Rules Used by SLAAC

Table 1: Original Problems

Problem # Prefix MAC Address
1 2001:0DB8:9283:0102::/64 000C.1234.5678
2 3000:D0D0:0D0D:BEEF::/64 0003.0303.0303
3 2001:0DB8:0000:0000::/64 0C00.BEEF.CAFE
4 3100:0202:0101:00AA::/64 0013.0B0B.B0B0
5 2001:0DB8:0000:0000::/64 2000.9876.5432

Table 2: Unabbreviated Unicast Addresses Found with SLAAC

Problem # Unabbreviated Unicast IPv6 Address
1 2001:0DB8:9283:0102:020C12FF:FE34:5678
2 3000:D0D0:0D0D:BEEF:0203:03FF:FE03:0303
3 2001:0DB8:0000:0000:0E00:BEFF:FEEF:CAFE
4 3100:0202:0101:00AA:0213:0BFF:FE0B:B0B0
5 2001:0DB8:0000:0000:2200:98FF:FE76:5432

 

Table 3: Abbreviated Unicast Addresses Found with SLAAC

Problem # Abbreviated Unicast IPv6 Address
1 2001:0DB8:9283:0102:020C12FF:FE34:5678
2 3000:D0D0:0D0D:BEEF:0203:03FF:FE03:0303
3 2001:0DB8:0000:0000:0E00:BEFF:FEEF:CAFE
4 3100:0202:0101:00AA:0213:0BFF:FE0B:B0B0
5 2001:0DB8:0000:0000:2200:98FF:FE76:5432

 

Table 4: Solicited Node Multicast Addresses

Solicited Node Multicast Addresses
1 FF02::1:FF34:5678
2 FF02::1:FF03:303
3 FF02::1:FFEF:CAFE
4 FF02::1:FF0B:B0B0
5

FF02::1:FF76:5432

 

 

 

IPv6 Icky EUI-64 Drill 1
IPv6 Shrinker 1
certskills
By certskills April 1, 2017 09:50
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7 Comments

  1. keith February 3, 11:23

    the problem was to write shortest abreviated ipv6 address. answer shows unabreviated version of addresses.

    2001:db8:9283:102:20c:12ff:fe34:5678
    3000:d0d0:d0d:beef:103:3ff:fe03:3030
    2001:db8::f00:beff:feef:cafe
    3100:202:1010:aa:213:bff:fe0b:b0b0
    2001:db8::2200:98fe:ef76:5432

    Reply to this comment
  2. Jack Mac February 10, 16:02

    We can also take it to the next step and “shrink” the address to what the router will display:

    1 — 2001:DB8:9283:102:20C:12FF:FE34:5678

    2 — 3000:D0D0:D0D:BEEF:103:3FF:FE03:3030

    3 — 2001:DB8::E00:BEFF:FEEF:CAFE

    4 — 3100:202:1010:AA:213:BFF:FE0B:B0B0

    5 — 2001:DB8::2200:98FF:FE76:5432

    Reply to this comment
  3. John November 5, 13:26

    table 3 row 5 second quartet is 0DB8, abbreviated form is DB8.

    Also, column heading says “Unabbreviated Unicast IPv6 Addresses” should say “Abbreviated Unicast IPv6 Addresses”

    Reply to this comment
  4. Michael December 4, 12:34

    When I check this exercise using PT I get an error when the 8th bit is 1 (the second Hex digit is odd: 1,3,5,7,9,B,D,F) I believe that if the 8th bit is 1 the MAC address is classified as multicast. A 0 is unicast.

    R1(config)#int gi0/1
    R1(config-if)#mac-add 0303.0303.0303
    % Malformed hex mac address

    Is this a PT issue or is it possible to manually set a multicast MAC address?

    Reply to this comment
    • certskills Author December 8, 13:52

      Michael,
      Thanks so much for the note.
      In this case, Packet Tracer is acting just like real gear. Indeed, the issue is the MAC address in problem 2 had the 8th bit set to 1, making it a multicast MAC address, and both real Cisco IOS and packet tracer reject using the MAC address. My mistake for using it in the lab.
      I just updated the lab exercise and answer post to use a unicast MAC, by the way.
      Thanks for letting me know!
      Wendell

      Reply to this comment
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