Embedded network packet data for use of alternative paths within a group of network devices

1. A system comprising a network device having processing circuitry and storage, wherein the processing circuitry has access to the storage and is configured to:

receive a network packet to be forwarded to a destination device;

store, within the network packet, visited node data identifying the network device as having been visited by the network packet;

identify, from among a plurality of egress links from the network device, a first link along a path to the destination device;

determine that the first link is inoperable;

identify, from among the plurality of egress links from the network device, a second link that is operable and is along an alternative path to the destination device; and

transmit the network packet over the second link.

2. The system of claim 1 , wherein the network device is a first network device, and wherein the system further comprises a second network device connected to the first network device over the second link, and wherein the second network device is configured to:

receive the network packet over the second link from the first network device;

update the visited node data to identify the second network device as having been visited by the network packet,

identify, from among a plurality of egress links from the second network device, a third link along a path to the destination device,

determine, based on the visited node data stored within the network packet, that the third link leads to a network device that has been previously visited by the network packet;

identify, from among the plurality of egress links from the second network device, a fourth link that is operable and is along a second alternative path to the destination device; and

transmit the network packet over the fourth link.

3. The system of claim 1 , wherein the network device is included within a plurality of interconnected network devices, and wherein to store the visited node data, the network device is further configured to:

insert a visited node vector into the network packet, wherein the visited node vector includes one bit associated with each of the plurality of interconnected devices.

4. The system of claim 1 , wherein to identify the second link, the processing circuitry is further configured to:

determine that the second link does not connect to another device that the network packet has previously visited.

5. The system of claim 1 , wherein to store data identifying the network device, the processing circuitry is further configured to:

determine whether the packet includes any data identifying previously-visited devices.

6. The system of claim 5 , wherein if the packet does not include any data identifying previously-visited devices, the processing circuitry is further configured to:

insert visited node data into the network packet and encode the network packet to indicate that the network packet includes the visited node data.

7. The system of claim 5 , wherein if the packet does include data identifying previously-visited devices, the processing circuitry is further configured to:

identify visited node data within the network packet; and

update the visited node data in the network packet.

8. The system of claim 1 , wherein to identify the second link, the processing circuitry is further configured to:

identify, without notifying a control plane, the second link.

9. A network device having processing circuitry and storage, wherein the processing circuitry has access to the storage and is configured to:

receive a network packet to be forwarded to a destination device;

store, within the network packet, data identifying the network device as having been visited;

identify, from among a plurality of egress links from the network device, a first link along a path to the destination device;

determine that the first link is inoperable;

identify, from among the plurality of egress links from the network device, a second link that is along an alternative path to the destination device and does not connect to another device that the network packet has previously visited; and

transmit the network packet over the second link.

10. The network device of claim 9 , wherein the network device is included within a plurality of interconnected network devices, and wherein to store data identifying the network device as having been visited, the network device is further configured to:

insert a visited node vector into the network packet, wherein the visited node vector includes one bit associated with each of the plurality of interconnected devices.

11. The network device of claim 9 , wherein to store data identifying the network device as having been visited, the network device is further configured to:

determine whether the packet includes any data identifying previously-visited devices.

12. The network device of claim 11 , wherein if the packet does not include any data identifying previously-visited devices, the network device is further configured to:

insert visited node data into the network packet.

13. The network device of claim 11 , wherein if the packet does include data identifying previously-visited devices, the network device is further configured to:

identify visited node data within the network packet; and

update the visited node data in the network packet.

14. The network device of claim 9 , wherein to identify the second link, the processing circuitry is further configured to:

identify, without notifying a control plane, the second link.

15. A computer-implemented method comprising:

receiving, at a network device, a network packet to be forwarded to a destination device;

storing, within the network packet, data identifying the network device as having been visited by the packet;

identifying, from among a plurality of egress links from the network device, a first link along a path to the destination device;

determining that the first link is inoperable;

identifying, from among the plurality of egress links from the network device, a second link that is along an alternative path to the destination device and does not connect to another device that the network packet has previously visited; and

transmitting the network packet over the second link.

16. The computer-implemented method of claim 15 , wherein the network device is included within a plurality of interconnected network devices, and wherein the computer-implemented further comprises:

inserting a visited node vector into the network packet, wherein the visited node vector includes one bit associated with each of the plurality of interconnected devices.

17. The computer-implemented method of claim 15 , further comprising:

determining whether the packet includes any data identifying previously-visited devices.

18. The computer-implemented method of claim 17 , further comprising: wherein if the packet does not include any data identifying previously-visited devices, the instructions cause the processing circuitry to:

inserting visited node data into the network packet based on the network packet not including any data identifying previously-visited devices.

19. The computer-implemented method of claim 17 , further comprising:

identifying visited node data within the network packet; and

updating the visited node data in the network packet.

20. The computer-implemented method of claim 15 , wherein identifying the second link further includes:

identifying the second link without notifying a control plane.