Problem Establishing a GRE Tunnel Checklist

Problem

Description: This checklist provides the links and commands for troubleshooting a case study about a problem establishing a Generalized Multiprotocol Label Switching (GMPLS) label-switched path (LSP). Specifically, the configuration of the data channel is incorrect because the configuration includes different interface types at both ends of the tunnel. The principles and solution used in this case study also apply to control channel configuration.

The checklist includes the links to a brief summary of GRE tunnels within the context of GMPLS, an example network scenario, and more detailed information about the commands used to troubleshoot and resolve the problem.

The troubleshooting process described in this case study should not be followed rigidly; it is a basis from which you can develop your own process to suit your particular situation. (See Table 1

Solution

Table 1: Problem Establishing a GRE Tunnel Checklist

Tasks	Command or Action
Troubleshooting GMPLS and GRE Tunnel
Symptom	show mpls lsp show rsvp session
Cause	The cause of the problem with the GMPLS LSP is the configuration of different interface types at both ends of the GMPLS data channel.
Troubleshooting Commands	show mpls lsp extensive show rsvp session detail show link-management peer show link-management te-link show configuration protocols mpls monitor start`filename` show log `filename`
Solution	Configure both ends of the data channel with the same switching type. show configuration protocols link-management show mpls lsp show link-management te-link
Conclusion	Both ends of a GMPLS data must be the same encapsulation or interface type.
Router Configurations	show configuration \| no-more