After IGP and BGP questions, I prepared basic list of MPLS interview questions which could help you to clear your next level. In the up coming post, I will be covering switching. Below is the list of questions:-
1. What is the difference between VPN and MPLS?
2. What is MPLS and why it is being so popular in short time?
3. What is the protocol used by MPLS?
4. MPLS works on which layer?
5. What is the difference between P and PE router?
6. Can I make my PE router as P?
7. Two routers are having 4 equal cost links, how many ldp sessions will be established?
8. My LDP router id, OSPF router id and BGP router id is different, will it work to forward the traffic of customers or not?
9. What is Penultimate Hop Popping and why it is required? Which router performs the PHP function?
10. I am receiving aggregate label, what does it mean?
11. What are the different types of labels?
12. How to make customer route unique?
13. What is the difference between RD and RT?
14. Can I assign a same RD to two different customers?
15. Is RD travels in route update?
16. My customer is having three branches and all are attached to three different PEs, In this case can I use the different vrf names?
17. What is downstream on demand?
18. How to filter MPLS labels?
19. What is the default range of MPLS labels in Cisco routers? How to extend that range?
20. Without route reflector can I implement MPLS?
21. What is the difference between VPNv4 and IPv4 address family?
22. What is MP-iBGP? Can we use normal BGP in lieu of MP-iBGP?
23. What is LIB, LFIB?
24. What is CEF and without enabling CEF, can we make MPLS work?
25. I am receiving end to end customer routes on various PE but not able to ping those routes, what’s could be the problem?
26. What is explicit null and implicit null?
27. Default timers of LDP?
28. Does LDP require OSPF, IS-IS or BGP?
29. In neighbor discovery command, I am receiving only xmit, what does it mean?
30. What is transport address?
31. What is the RFC of MPLS?
32. Why MPLS is called multi protocol?
33. What is the difference between MPLS, SSL and IPSec?
34. I am using different vendor products and want to implement TDP, what type of challenges will you face?
35. Does MPLS support IPv6?
36. Can I use the existing IPv4 MPLS backbone for IPv6?
37. Define various troubleshooting commands in MPLS?
38. What is forward equivalence class aka FEC?
39. What is adjacency table?
40. Difference between MPLS IP and MPLS Label Protocol LDP command?
41. If MPLS get disable, will it harm my IGP or IPv4 traffic?
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42. What is MPLS-TP?
43. What is downstream and upstream router in MPLS? 44. Difference between MPLS and MPLS-TP?
45. How Does LDP Initializes?
46. What is Cell Mode MPLS Over ATM?
47. Difference Between VC Based Multiplexing And Logical Link Control Encapsulation in ATM?
48. Basics of ATM?
49. ATM is packet or circuit switching?
50. Is LDP Required for VPNv4 Labels?
51. What will happen if you see your PE loopback in vpnv4 table?
52. What is Bidirectional Forwarding Detection?
53. Different types of PseudoWire?
54. Modes of EoMPLS (Ethernet over MPLS)
55. What is L2VPN Over Metro Ethernet?
56. What is E-VPN(Ethernet VPN)?
57. what is FEC in traditional IP routing and MPLS?
58. How does CEF understand overlapping of ip addresses ?
59. What is the difference between Optimum, Fast and CEF Switching?
60. Advantages of MPLS.
61. Define CEF FIB table entries.