Junos Cup 2014
Junos Cup 2014

Tournament 3: Mexico Challenge & Solution: Displaying Remote MAC Addresses

[ Edited ]
‎06-26-2014 07:19 AM

Country Flag: MEXICO


Author: Antonio Sánchez-Monge


Title: Displaying Remote MAC Addresses


Type: Enterprise


Difficulty: Medium (1 point).


Technical Description: Enable the dynamic discovery of the neighbor link MAC addresses between R1 and R2.






Challenge Instructions:

For this challenge, you need to start the topology called: “MEXICO – Displaying Remote MAC Addresses”.


You need to find a way to display the MAC address of the R2 interface ge-0/0/0 by executing an operational show command at R1, similar to the following:


juniper@R1> show [...]

/* This output contains the MAC address of R2 ge-0/0/0 */


You can modify the configuration of both devices, but only under the following conditions:


-       You are not allowed to add an address family to the ge-0/0/0 interface on any of the routers.

-       You are not allowed to mention the MAC address of R2 anywhere in R1’s configuration.


To solve this challenge please submit the whole procedure – thus any configuration changes and the show command at R1 that contains the output showing the MAC address of R2 ge-0/0/0.


NOTE: If you have issues connecting to the Junosphere topology please check Junosphere Technical documentation, or request assistance in the Junosphere forum 

Send an email with your proposed solution to junos-cup@juniper.net:

  •  The subject should be “<country-name-of-the-challenge> -  <your-full-name>”. For example: “Brazil – Wolfgang Amadeus Mozart”.
  • In the email body, please include your proposed solution, along with your first and last name and complete mailing address including zip/postal code and your shirt size (S, M, L, XL, XXL, XXXL) (Only if you haven’t already submitted your address/shirt size on a previous submission)


Deadline to Respond: Tuesday, 1st of July 23:59:59 Pacific Daylight Time (PDT) 

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Some additional notes:

  • You can try to solve and submit answers for as many active challenges as you wish
  • The answers will be read by the organization right after the deadline
  • The challenge instructions are final, and no additional information or tips will be provided before the publication of the solution and the winner list. Please don’t expect a reply from junos-cup@juniper.net.
  • If you feel that your initial solution is wrong or incomplete, you can send up to three messages for the same challenge, but please note that only your last message (received before the deadline) will be read.
  • If you think there is an error in the definition of the challenges, please send us an email with subject (“<country-name> ERROR”); if there is no reply, then it’s likely an intentional condition of the challenge, rather than an error.




Execute at both R1 and R2:


juniper@R1> configure

juniper@R1# set protocols oam ethernet link-fault-management interface ge-0/0/0   

juniper@R1# commit and-quit


juniper@R1> show oam ethernet link-fault-management ge-0/0/0


  Interface: ge-0/0/0

    Status: Running, Discovery state: Send Any

    Peer address: 00:05:86:71:a5:00 <<<<<

    Flags:Remote-Stable Remote-State-Valid Local-Stable 0x50

    Remote entity information:

      Remote MUX action: forwarding, Remote parser action: forwarding

      Discovery mode: active, Unidirectional mode: unsupported

      Remote loopback mode: unsupported, Link events: supported

      Variable requests: unsupported



Julie Wider
Advocacy Manager
Twitter: @JNetCommunity & @jawider