Interview with a senior network engineer

This is an interview question for someone in early October. After-sales position: Senior Network Engineer. The interviewer is a three-member CCIE. The interview lasted more than two hours, and he was very impressed. Now this offer is basically determined, and the subject is still considering situations such as treatment and work pressure before deciding whether to accept this offer. the subject also posted interview questions on his blog, so I am also daring to post them.

1. In the current 6509 and 7609, The sup720 switched bandwidth to 720 GB. Can it be said that 7609/6509 can replace part of the GSR status?

2. Which route table of ISIS level1 includes? When there are multiple levels-1-2 exits, Where do other routes learn from? How do I select routes?

3. MPLS L3 VPN. What should I do if I want to allow one-way mutual access between two different VPNs?

4. Can I talk about the concept of cross-origin MPLS L3 VPN?

5. How can an MPLS L3 VPN user meet the Internet requirements? What are the implementation methods? What are the characteristics?

6. MPLS L3 VPN. What should I do if I want to allow one-way mutual access between two different VPNs?

7. What are the characteristics of L3 VPN and L2 VPN? Which of the following modes do you think is promising?

8. Let's talk about the differences between ISIs and OSPF in various aspects.

9. What are the reasons for selecting Isis and OSPF for a backbone network or man?

10. What are common BGP routing principles? How can I work with backbone networks and man networks?

11. If max path is added to BGP, which BGP routing attribute will this option be applied before?

12. Why does the pop and man egress of the backbone network need to be set to next-hop-self?

13. There are four router interfaces between the two as instances. One of the routers learns one network from ebgp and the other from ibgp to the same network. Which one is the route? Which of the following attributes has an impact? Which one should I choose if I add med below ebgp in ibgp? Why?

14. What is the difference between local-Pre and weight?

15. Can BGP achieve load balancing? If yes, what are the methods?

16. Can I compare med among multiple as instances? If yes, do you need any prerequisites? If so, what are the prerequisites?

17. Can med be combined with the IGP metric value in? If yes, how can this problem be solved?

18. there are still 10 minutes to limit for the cutover and the cutover is not successful. The Bureau has urged you to roll back. However, if you try to solve these problems for another 5 minutes, what is your choice?

19. How to deploy the QoS of the backbone network? What kind of backbone network do you think is congested?

20. Which of the following do you think is better for engineering and maintenance?

21. What are the mechanisms used by L3 networks and L2 Networks to process loops?

22. How many trees are generated by L2 switches in general?

23. What is the spanning tree mode of 3550? What is the number of spanning trees?

24. According to your experience, when the traffic on the GE port reaches, you can think of congestion as a problem? When the traffic reaches 2.5g POS port, you can think of congestion?

In addition, I asked about how to handle some events in project implementation, and whether there were some failed experiences and experiences, I also asked what was the most difficult event at work and how to handle it. Of course, there are also some conversations that affect each other in a peaceful atmosphere.