CCIE SP MPLS FAQ: MPLS Troubleshooting
Q1. What are the prerequisites for successful MPLS deployment?
Q2. What are the reasons that a TDP neighbor would not be discovered?
Q3. Which command can you use to display TDP neighbors?
Q4. What are the reasons that a TDP session might not start?
Q5. In some cases, the LSR runs TDP with the neighbors but does not assign any labels locally. What is the reason for this behavior?
Q6. Why would an LSR assign a label but not propagate it to its peers?
Q7. Why would an LSR label IP packets that it receives through one interface but not through another?
Q8. How would you discover a broken LSP in your network?
Q9. Why would the introduction of MPLS break the propagation of large IP datagrams? How would you discover this symptom?