You can verify a few MPLS interface parameters with the command show mpls interfaces detail. First, you can verify whether LDP is enabled on the interface. Second, you can verify whether the interface is enabled for RSVP with extensions so that a TE tunnel can cross the interface. Third, you can verify whether BGP with MPLS label advertisement is enabled on the interface. Finally, you can determine the MPLS MTU value of the interface, which is mentioned in the output. Look at Example 13-13 to see the output of the show mpls interfaces detail command.
london#show mpls interfaces detail Interface Ethernet0/0/0: IP labeling enabled (ldp): Interface config LSP ...