Junos Cup 2014
Junos Cup 2014

Tournament 2: Cameroon Challenge & Solution: BGP, MPLS & FIB Scaling

[ Edited ]
‎06-19-2014 07:21 AM

Country Flag: CAMEROON


Author: Haofeng Zhang


Title: BGP, MPLS, and FIB scaling


Type: Service Provider


Difficulty: Medium (1 point).


Technical Description: Reduce the FIB size of R2, while maintaining connectivity between R1 and R3.





Challenge Instructions:

For this challenge, you need to start the topology called: “CAMEROON - BGP, MPLS and FIB Scaling”.


You are the operator of network AS 65100. Your ASBR R2 is getting external BGP routes from your peer AS6 5002, and all these routes should be advertised to R3.


Because R2 is a low-end router that cannot support a FIB with these BGP routes in hardware, you need to configure R2/R3 in your network in order to achieve the following requirements:

  1. Keep all the BGP routes in R2 and R3 RIB; but DO NOT download any BGP routes (not a single one) to R2’s forwarding table (FIB).
  2. Make sure R3 can reach all these BGP destinations advertised by R1.
  3. You cannot configure any static, aggregate, or generate routes on any router in this challenge.
  4. You should not redistribute the BGP routes in any other protocol.
  5. For operational reasons, you cannot introduce any new signaling protocol in the network, not even configure static LSPs.
  6. You can only change the R2/R3 configuration. You are not authorized to configure R1.


To Verify:

  1. Check that both R2 and R3 get all ~200 BGP routes:


juniper@R2> show route summary

Autonomous system number: 65100

Router ID:


inet.0: 208 destinations, 209 routes (208 active, 0 holddown, 0 hidden)

              Direct:      4 routes,      4 active

               Local:      3 routes,      3 active

                OSPF:      2 routes,      2 active

                 BGP:    200 routes,    199 active


  1. Only very few (20~30) IPv4 FIB entries in R2’s forwarding table:


juniper@R2> show pfe route summary

Slot 0


IPv4 Route Tables:

Index         Routes     Size(b)

--------  ----------  ----------

Default           26        2388

1                 12        1100

2                  6         548

3                  5         456


  1. Ping test from R3 to R1 works fine. You should be able to reach all prefixes including - from R3:


juniper@R3> ping source count 1

PING ( 56 data bytes

64 bytes from icmp_seq=0 ttl=63 time=14.175 ms


--- ping statistics ---

1 packets transmitted, 1 packets received, 0% packet loss

round-trip min/avg/max/stddev = 14.175/14.175/14.175/0.000 ms


To solve this challenge, what are the set commands configured and at which router?


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, 24th of June 23:59:59 Pacific Daylight Time (PDT)

Timezone Converter
Current PDT Time


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.



At R2:

set policy-options policy-statement no-bgp from protocol bgp

set policy-options policy-statement no-bgp then reject

set routing-options forwarding-table export no-bgp

set protocols bgp group int family inet labeled-unicast

set interfaces ge-0/0/2 unit 0 family mpls

At R3:

set protocols bgp group int family inet labeled-unicast

set interfaces ge-0/0/1 unit 0 family mpls



Julie Wider
Advocacy Manager
Twitter: @JNetCommunity & @jawider