Enabled MPLS on relevant interfaces on the PE and P devices to enable the MPLS VPN service.
Check the NE40E configurations onsite and find that the lsp-trigger ip-prefix prefix-name command is configured The user has defined a prefix list that allows only the loopback address of the local device, which causes the fault.The user thinks that LSP sessions can be globally established after each local loopback address is configured in the prefix list. The lsp-trigger ip-prefix command is incorrectly configured, resulting in LSP establishment failures in ingress and egress of some devices. After some uplinks are disconnected, the NE40E becomes a transit node along an LSP. By default, LDP does not filter routes when establishing an LSP on the transit node. Therefore, some LSPs are displayed.