Interview Questions

I act as proctor today for interview someone who want to join our team. There are couple CCIE holder, CCNP, CCIE candidat. I can't identify how they know each protocol and how deep. So there is the question for them! It's all question I faced while troubleshoot. (It's all IOS not Junos)

Q1, One junior engineer report that he can saw LSA in the LSDB, but he can't find out the route in routing table via sh ip route ! The question is "How make this happen" and How did you fix it ?

Q2, In MPLS VPN network, One junior engineer report that he can saw remote site routing update in local site CE router, but ping from local to remote isn't work. The question is "How make this happen" and How did you fix it ?

Q3, One junior engineer report that he saw one L2 port in cisco Layer 2 switch in forwarding status, but no traffic is transmit. The question is "How make this happen" and How did you fix it ?

Those question are very wide, the answer could be different from you. For Q1, it's not a IOS bug. Leave your answer. I will put my answer if someone interesting!