Which two reasons would cause an LSP to break between two PE routers? (Choose two.)
Which two reasons would cause an LSP to break between two PE routers? (Choose two.)
There are two primary reasons that would cause a Label Switched Path (LSP) to break between Provider Edge (PE) routers. The first reason is a lost LDP (Label Distribution Protocol) adjacency. LDP is crucial for the establishment of LSPs as it distributes labels which are used to make forwarding decisions in MPLS networks. Without an LDP adjacency, label distribution cannot occur properly, leading to a break in the LSP. The second reason is MPLS not being enabled. MPLS must be enabled on the interfaces involved in the LSP; if MPLS is not enabled, the data cannot be labeled and forwarded properly, causing the LSP to break.
I thought A and E. Anyway, it do not think LSP break with prefix mismatch, so personally C is wrong. A & E seem best here
Im not sure on A because of the word "adjacency". I mean LDP issues yes, would cause the break between PE routers but adjacency?
https://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/mpls/23565-troubleshoot-mpls-vpn.html#cause I think its CE