JN0-106 Routing Fundamentals Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Increase the OSPF preference for 10.1.1.0/24 to 175

  Why this is correct

  In Junos, route preference is the first criterion in the route selection process. OSPF internal routes default to a preference of 10, while iBGP routes default to 170, so the router installs the OSPF route even if the BGP route has a better path out of the loop. By raising OSPF preference for 10.1.1.0/24 to 175, you make OSPF less desirable than BGP (170), allowing the iBGP route to become active and use a next hop that exits the loop. This targeted override of the default preference for a specific prefix resolves the loop without affecting other routes.

• ✗

  Add a static route for 10.1.1.0/24 with next-hop 10.2.2.2

  Why it's wrong here

  Adding a static route to 10.1.1.0/24 with next-hop 10.2.2.2 would install a route with a preference of 5, which is more preferred than both OSPF (10) and iBGP (170), so it would become active. However, static routes are not automatically advertised into BGP unless a policy explicitly exports them; doing so would require additional configuration and could introduce a new set of problems. Even if installed, this only changes the local forwarding decision and does not address the underlying BGP route preference issue, so the loop remains for other iBGP peers or recurs when the static route is not propagated.

• ✗

  Configure 'set protocol bgp group internal-mesh local-address 10.2.2.2' to set next-hop to self

  Why it's wrong here

  Configuring 'set protocol bgp group internal-mesh local-address 10.2.2.2' changes the source IP used for the BGP session and can influence the next-hop in BGP updates if combined with 'next-hop self', but by itself it does not affect which route is active in the routing table. In this scenario, the OSPF route is still preferred (preference 10 vs 170), so the BGP route remains inactive and the forwarding loop persists. Next-hop manipulation is a matter of BGP route propagation, not route preference, and therefore cannot break a loop caused by an IGP route winning over iBGP.

• ✗

  Use route reflection to break the loop

  Why it's wrong here

  Route reflection is an iBGP scalability feature that allows a route reflector to re-advertise iBGP-learned routes to clients, reducing the number of sessions in a full mesh; it does not alter route preference or change how a router selects between OSPF and BGP routes. Since the loop is caused by OSPF having a lower preference (10) than iBGP (170), reflecting routes does not change the active route — the same OSPF route still wins. In fact, if the reflected route points back into the same loop, it could perpetuate the problem rather than solve it. The correct fix must influence the route selection process, such as adjusting preference, not merely reorganize how BGP routes are exchanged.

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