Processing segment routing packets with two policy processing instructions in a segment routing domain

1. A method, comprising:

receiving, by a network device, a packet;

determining, by the network device, whether a next header of the packet is an Internet protocol (IP) header, an Internet control message protocol (ICMP) header, or a segment routing header;

determining, by the network device and when the next header of the packet is the ICMP header, that the packet is an operations, administration, and maintenance (OAM) packet;

determining, by the network device and when the next header of the packet is the ICMP header, whether policy processing of the packet is set to ultimate segment decapsulation;

discarding, by the network device, the packet when the policy processing of the packet is not set to ultimate segment decapsulation;

providing, by the network device and when the policy processing of the packet is set to ultimate segment decapsulation, the packet to a routing component of the network device for OAM processing;

performing, by the routing component of the network device, the OAM processing to generate a processed packet; and

forwarding, by the network device, the processed packet toward a destination.

2. The method of claim 1 , further comprising:

determining, when the next header of the packet is the segment routing header, that the packet is an operations, administration, and maintenance (OAM) packet;

determining, when the next header of the packet is the segment routing header, whether policy processing of the packet is set to ultimate segment pop or ultimate segment decapsulation;

providing, when the policy processing of the packet is set to ultimate segment pop or ultimate segment decapsulation, the packet to a routing component of the network device for OAM processing;

performing, by the routing component of the network device, OAM processing of the packet to generate a processed packet; and

forwarding the processed packet toward the destination.

3. The method of claim 1 , further comprising:

determining, when the next header of the packet is the segment routing header, that the packet is an operations, administration, and maintenance (OAM) packet;

determining, when the next header of the packet is the segment routing header, whether policy processing of the packet is set to ultimate segment pop;

popping the segment routing header of the packet when the policy processing of the packet is set to ultimate segment pop;

processing the packet after popping the segment routing header of the packet, to generate a processed packet; and

forwarding the processed packet toward the destination.

4. The method of claim 1 , further comprising:

determining, when the next header of the packet is the segment routing header, whether policy processing of the packet is set to ultimate segment decapsulation;

decapsulating an outer header of the packet when the policy processing of the packet is set to ultimate segment decapsulation;

processing the packet after decapsulating the outer header of the packet, to generate a processed packet; and

forwarding the processed packet toward the destination.

5. The method of claim 4 , further comprising one of:

processing the segment routing header of the packet when the policy processing of the packet is not set to ultimate segment decapsulation; or

discarding the packet when the policy processing of the packet is not set to ultimate segment decapsulation.

6. The method of claim 1 , further comprising:

performing, when the next header of the packet is the segment routing header, ultimate segment pop processing on the packet when the packet includes more than one segment routing header.

7. A network device, comprising:

one or more memories; and

one or more processors to:

receive a packet;

determine whether a next header of the packet is an Internet protocol (IP) header, an Internet control message protocol (ICMP) header, or a segment routing header;

determine, when the next header of the packet is the ICMP header, whether policy processing of the packet is set to ultimate segment decapsulation;

discard the packet when the policy processing of the packet is not set to ultimate segment decapsulation;

provide, when the policy processing of the packet is set to ultimate segment decapsulation, the packet to a routing component of the network device for operations, administration, and maintenance (OAM) processing;

perform the OAM processing to generate a processed packet; and

forward the processed packet toward a destination.

8. The network device of claim 7 , wherein the network device includes an egress network device in a segment routing domain.

9. The network device of claim 7 , wherein the one or more processors are further to:

determine, when the next header of the packet is the segment routing header, whether the packet includes more than one segment routing header;

discard the packet when the policy processing of the packet is set to ultimate segment pop and the packet fails to include more than one segment routing header; and

perform ultimate segment pop processing on the packet when the policy processing of the packet is set to ultimate segment pop and the packet includes more than one segment routing header.

10. The network device of claim 9 , wherein the one or more processors are further to:

forward the packet toward the destination after performing the ultimate segment pop processing on the packet.

11. The network device of claim 7 , wherein the one or more processors are further to:

determine, when the next header of the packet is the IP header, that a format of the packet includes the IP header followed by a first segment routing header and a second segment routing header; and

perform ultimate segment pop processing on the packet based on the format of the packet.

12. The network device of claim 11 , wherein the one or more processors are further to:

forward the packet toward the destination after performing the ultimate segment pop processing on the packet.

13. The network device of claim 7 , wherein the packet includes a set of encoded instructions that dictate a path for the packet.

14. The network device of claim 7 , wherein the one or more processors are further to:

determine, when the next header of the packet is the IP header, whether policy processing of the packet is set to ultimate segment decapsulation;

discard the packet when the policy processing of the packet is not set to ultimate segment decapsulation;

decapsulate an outer header of the packet when the policy processing of the packet is set to ultimate segment decapsulation;

process the packet after decapsulating the outer header of the packet, to generate a processed packet; and

forward the processed packet toward a destination.

15. A non-transitory computer-readable medium storing a set of instructions, the set of instructions comprising:

one or more instructions that, when executed by one or more processors of a network device, cause the network device to:

receive a packet that includes a set of encoded instructions that dictate a path for the packet;

determine whether a next header of the packet is an Internet protocol (IP) header, an Internet control message protocol (ICMP) header, or a segment routing header;

determine, when the next header of the packet is the ICMP header, whether policy processing of the packet is set to ultimate segment decapsulation;

discard the packet when the policy processing of the packet is not set to ultimate segment decapsulation;

provide, when the policy processing of the packet is set to ultimate segment decapsulation, the packet to a routing component of the network device for operations, administration, and maintenance (OAM) processing;

perform the OAM processing to generate a processed packet; and

forward the processed packet toward a destination.

16. The non-transitory computer-readable medium of claim 15 , wherein the one or more instructions further cause the network device to:

determine, when the next header of the packet is the segment routing header, that the packet is an operations, administration, and maintenance (OAM) packet;

determine, when the next header of the packet is the segment routing header, whether policy processing of the packet is set to ultimate segment pop or ultimate segment decapsulation;

provide, when the policy processing of the packet is set to ultimate segment pop or ultimate segment decapsulation, the packet to a routing component of the network device for OAM processing;

perform, with the routing component, OAM processing of the packet to generate a processed packet; and

forward the processed packet toward the destination.

17. The non-transitory computer-readable medium of claim 15 , wherein the one or more instructions further cause the network device to:

determine, when the next header of the packet is the segment routing header, whether policy processing of the packet is set to ultimate segment pop;

pop the segment routing header of the packet when the policy processing of the packet is set to ultimate segment pop;

process the packet after popping the segment routing header of the packet, to generate a processed packet; and

forward the processed packet toward the destination.

18. The non-transitory computer-readable medium of claim 15 , wherein the one or more instructions further cause the network device to:

determine, when the next header of the packet is the segment routing header, whether policy processing of the packet is set to ultimate segment decapsulation;

decapsulate an outer header of the packet when the policy processing of the packet is set to ultimate segment decapsulation;

process the packet after decapsulating the outer header of the packet, to generate a processed packet;

forward the processed packet toward the destination; and

discard the packet when the policy processing of the packet is not set to ultimate segment decapsulation.

19. The non-transitory computer-readable medium of claim 15 , wherein the one or more instructions further cause the network device to:

determine, when the next header of the packet is the segment routing header, whether the packet includes more than one segment routing header;

discard the packet when the policy processing of the packet is set to ultimate segment pop and the packet fails to include more than one segment routing header;

perform ultimate segment pop processing on the packet when the policy processing of the packet is set to ultimate segment pop and the packet includes more than one segment routing header; and

forward the packet toward the destination after performing the ultimate segment pop processing on the packet.

20. The non-transitory computer-readable medium of claim 15 , wherein the network device includes an egress network device in a segment routing domain.