Target fec (forwarding equivalence class) stack based fec query in segment routing environments

An apparatus comprising:

• an interface for transmitting packets on an LSP (Label Switched Path);
• a processor for generating a trace request at an initiator node configured for segment routing, the trace request comprising a query for FEC (Forwarding Equivalence Class) information, transmitting said trace request on a path comprising at least one node wherein FEC details for the node are unknown by the initiator node, and processing a response to said trace request comprising the FEC information;
• and
• memory for storing the FEC information.

Logic encoded on one or more non-transitory computer readable media for execution and when executed operable to:

• generate a first trace request at an initiator node configured for segment routing, said first trace request comprising a query for FEC (Forwarding Equivalence Class) information;
• transmit said first trace request on a path comprising at least one node wherein FEC details for the node are unknown by the initiator node;
• process a response to said first trace request comprising the FEC information;
• transmit a second trace request with the FEC information;
• and
• process a response to said second trace request providing FEC validation.