LSP ping and traceroute for bypass tunnels

1. A non-transitory computer-readable medium storing instructions, the instructions comprising:

one or more instructions which, when executed by a processor, cause the processor to:

assemble an echo request for a functional label switched path (LSP),

the echo request including directions for a transit node in the functional LSP to forward the echo request via a bypass path associated with the transit node and directions for an egress node of the LSP to send an echo reply that indicates that the echo request was received,

the echo request including an indication to forward the echo request along a Resource Reservation Protocol (RSVP) bypass path; and

send the echo request to the transit node via the functional LSP.

2. The non-transitory computer-readable medium of claim 1 , where the instructions further include:

one or more instructions to receive the echo reply from the egress node, where the echo reply includes an indication that the echo request was received via the bypass path associated with the transit node.

3. The non-transitory computer-readable medium of claim 1 , where the instructions further include:

one or more instructions to indicate a bypass route failure if the echo reply is not received from the egress node within a particular time period.

4. The non-transitory computer-readable medium of claim 1 , where the one or more instructions to assemble the echo request include:

one or more instructions to include the directions for the transit node and the directions for the egress node in an multiprotocol label switching (MPLS) shim header.

5. The non-transitory computer-readable medium of claim 1 , where the one or more instructions to assemble the echo request include:

one or more instruction to identify the transit node using a time to live (TTL) field in the echo request.

6. The non-transitory computer-readable medium of claim 1 , where the instructions further include:

one or more instructions to receive the echo reply from the egress node; and

one or more instructions to determine, based on the echo reply, if another transit node should be tested.

7. A method comprising:

assembling, by a network device, an echo request,

the echo request including an instruction for a node in a functional label switched path (LSP) to forward the echo request via a bypass path associated with the node and an instruction for an egress node of the LSP to send an echo reply that indicates that the echo request was received via the bypass path,

the instruction for the node including a time to live (TTL) field that is used to deliver the echo request to the node; and

sending, by the network device, the echo request to the other node.

8. The method of claim 7 , where the echo request includes one of a multiprotocol label switching (MPLS) ping or an MPLS trace.

9. The method of claim 7 , where the instruction for the node includes:

an indication to forward the echo request along a Resource Reservation Protocol (RSVP) bypass path.

10. The method of claim 7 , further comprising:

receiving, from the egress node, the echo reply; or

determining that the echo reply was not received within a particular time period.

11. The method of claim 7 , further comprising:

providing, for presentation via a user interface, information indicating that the echo reply was received within the particular time period or information indicating that the echo reply was not received within the particular time period.

12. The method of claim 7 , further comprising:

repeating the assembling and the sending for multiple other nodes in the functional LSP.

13. The method of claim 7 , where the instruction to forward the echo request via a bypass path includes a multiprotocol label switching (MPLS) bypass test header that includes:

an experimental functions section to specify precedence for the echo reply, and

a time to live (TTL) value to indicate a number of hops the echo request may traverse in the functional LSP before using a bypass path.

14. The method of claim 7 , further comprising:

receiving the echo reply from the egress node; and

determining, based on the echo reply, if an additional node should be tested.

15. A method comprising:

sending, by a network device and via a functional label switched path (LSP), a datagram including an instruction for a node in the functional LSP to forward the datagram via a bypass path associated with the node and an instruction for an endpoint of the LSP to send a reply that indicates that the datagram was received via the bypass path,

the bypass path including a Resource Reservation Protocol (RSVP) bypass path;

receiving, by the network device, the reply; and

selectively providing, by the network device and for presentation on a user interface associated with the network device, an indication of a functionality of the bypass path,

the selectively providing including:

providing a first indication indicating that the bypass path associated with the node is functional when the reply is received within a particular time period; or

providing a second indication indicating that the bypass path associated with the node is not functional when the reply is not received within the particular time period.

16. The method of claim 15 , where the datagram includes one of:

a multiprotocol label switching (MPLS) ping, or

a MPLS trace.

17. The method of claim 15 , where the reply includes an indication that the datagram was received via the bypass path associated with the node.

18. The method of claim 15 , further comprising:

receiving, via a user interface, a command to assemble and send the datagram; and

assembling the datagram based on the command.

19. The method of claim 15 , where the datagram includes a multiprotocol label switching (MPLS) bypass test header that includes:

an experimental functions section to specify precedence for the echo reply, and

a time to live (TTL) value to indicate a number of hops the datagram may traverse in the functional LSP before using the bypass path.

20. The method of claim 15 , further comprising:

receiving the reply from the endpoint; and

determining, based on the reply, if another node should be tested.