The MPLS forwarding table enables MPLS to determine whether an MPLS packet received from an upstream neighbor contains an MPLS label that was advertised to that neighbor. If not, the packet is dropped. Each entry in the forwarding table has a spoof check field that specifies the type of checking that must be performed for the associated in label. The signaling protocol (BGP, LDP, or RSVP) that populates the entry in the MPLS forwarding table sets the spoof check field.
MPLS supports the following types of spoof checking:
You can use the show mpls forwarding command to view the spoof check field for an MPLS forwarding table entry.