# US 11,909,629 B2 · Seamless segment routing for multiprotocol label switching (MPLS) interworking > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,629 B2 - Document ID: US11909629B2 - Status: Granted - Kind: B2 - Application number: 18/045,565 - Filed: 2022-10-11 - Published: 2023-03-02 - Granted: 2024-02-20 - Earliest claimed: 2020-12-30 - Assignees: Juniper Networks, Inc. - Applicants: Juniper Networks, Inc. - Inventors: Shraddha Hegde; Salih K A - Web page: https://patentgrep.com/patent/US11909629B2 ## CPC - H04L 45/20: {Hop count for routing purposes, e.g. TTL} - H04L 45/24: Multipath - H04L 45/42: Centralised routing - H04L 45/741: Routing in networks with a plurality of addressing schemes, e.g. with both IPv4 and IPv6 - H04L 45/745: Address table lookup; Address filtering - H04L 69/22: Parsing or analysis of headers - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A network device may receive policy data identifying a first segment routing (SR) policy and a second SR policy. The first SR policy may be associated with a first path through a network and a first next hop, and the second SR policy may be associated with a second path through the network and a second next hop. The network device may advertise, to another device, reachability associated with the first next hop and the second next hop, and may receive, from the other device, a packet with a header. The network device may determine, from the header, data identifying the first next hop or the second next hop, without performing a lookup, and may cause the packet to be routed to a destination address, via the first path or the second path, based on the policy data associated with the first next hop or the second next hop. ## Claims ### Claim 1 A method, comprising: providing, by a first device and to a second device, information associated with reachability related to at least one next hop; receiving, by the first device and from the second device, a packet including information associated with a first next hop of the at least one next hop; decapsulating, by the first device, a header of the packet; determining, by the first device, based on decapsulating the header of the packet, and based on information associated with the first next hop, that the packet is to be routed based on a particular segment routing policy, of one or more segment routing policies associated with the first device; removing, by the first device, the header of the packet; adding, by the first device, without performing a lookup process, and based on determining that the packet is to be routed based on the particular segment routing policy, a new header to the packet, wherein the new header includes at least one of a first segment identifier list that identifies a first path associated with the first next hop or a second segment identifier list that identifies a second path associated with a second next hop of the at least one next hop, and wherein the new header further includes a first destination address associated with the first segment identifier list or a second destination address associated with the second segment identifier list; and causing, by the first device and based on the new header, the packet to be routed via a particular path associated with the particular segment routing policy. ### Claim 2 (depends on 1) The method of claim 1, further comprising: receiving policy data identifying the one or more segment routing policies, including the particular segment routing policy, that are associated with particular paths that include respective next hops. ### Claim 3 (depends on 1) The method of claim 1, wherein the particular segment routing policy identifies a particular next hop and a particular segment identifier list that identifies the particular path. ### Claim 4 (depends on 1) The method of claim 1, wherein the header further includes data identifying the second next hop, wherein data identifying the first next hop and the second next hop is included in the header based on advertising a reachability associated with the first next hop and the second next hop, and wherein the method further comprises: determining routing from data identified in the first next hop and the second next hop. ### Claim 5 (depends on 1) The method of claim 1, wherein the first segment identifier list is associated with the particular segment routing policy. ### Claim 6 (depends on 1) The method of claim 1, wherein the header that is decapsulated is associated with an extra Internet protocol version 6 (IPv6) header. ### Claim 7 (depends on 1) The method of claim 1, wherein the packet is associated with an application of the second device. ### Claim 8 A first device, comprising: one or more memories; and one or more processors to: provide, to a second device, information associated with reachability related to at least one next hop; receive, from the second device, a packet including information associated with a first next hop of the at least one next hop; decapsulate a header of the packet; determine, based on decapsulating the header of the packet, and based on the information associated with the first next hop, that the packet is to be routed based on a particular segment routing policy, of one or more segment routing policies associated with the first device; remove the header of the packet; add, without performing a lookup process and based on determining that the packet is to be routed based on the particular segment routing policy, a new header to the packet, wherein the new header includes at least one of a first segment identifier list that identifies a first path associated with the first next hop of the at least one next hop or a second segment identifier list that identifies a second path associated with a second next hop of the at least one next hop, and wherein the new header further includes a first destination address associated with the first segment identifier list or a second destination address associated with the second segment identifier list; and cause, based on the new header, the packet to be routed via a particular path associated with the particular segment routing policy. ### Claim 9 (depends on 8) The first device of claim 8, wherein the one or more processors are further to: receive policy data identifying the one or more segment routing policies, including the particular segment routing policy, that are associated with particular paths that include respective next hops. ### Claim 10 (depends on 8) The first device of claim 8, wherein the particular segment routing policy identifies a particular next hop and a particular segment identifier list that identifies the particular path. ### Claim 11 (depends on 8) The first device of claim 8, wherein the header further includes data identifying the second next hop, wherein data identifying the first next hop and the data identifying the second next hop is included in the header based on advertising a reachability associated with the first next hop and the second next hop, and wherein the one or more processors are further to: determine routing from data identified in the first next hop and the second next hop. ### Claim 12 (depends on 8) The first device of claim 8, wherein the first segment identifier list is associated with the particular segment routing policy. ### Claim 13 (depends on 8) The first device of claim 8, wherein the header that is decapsulated is an extra Internet protocol version 6 (IPv6) header. ### Claim 14 (depends on 8) The first device of claim 8, wherein the packet is associated with an application of the second device. ### Claim 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 first device, cause the first device to: provide, to a second device, information associated with reachability related to at least one next hop; receive, from the second device, a packet including information associated with a first next hop of the at least one next hop; decapsulate a header of the packet; determine, based on decapsulating the header of the packet, and based on the information associated with the first next hop, that the packet is to be routed based on a particular segment routing policy, of one or more segment routing policies associated with the first device; remove the header of the packet; add, without performing a lookup process and based on determining that the packet is to be routed based on the particular segment routing policy, a new header to the packet, wherein the new header includes at least one of a first segment identifier list that identifies a first path associated with the first next hop of the at least one next hop or a second segment identifier list that identifies a second path associated with a second next hop of the at least one next hop, and wherein the new header further includes a first destination address associated with the first segment identifier list or a second destination address associated with the second segment identifier list; and cause, based on the new header, the packet to be routed via a particular path associated with the particular segment routing policy. ### Claim 16 (depends on 15) The non-transitory computer-readable medium of claim 15, wherein the one or more instructions further cause the first device to: receive policy data identifying the one or more segment routing policies, including the particular segment routing policy, that are associated with particular paths that include respective next hops. ### Claim 17 (depends on 15) The non-transitory computer-readable medium of claim 15, wherein the particular segment routing policy identifies a particular next hop and a particular segment identifier list that identifies the particular path. ### Claim 18 (depends on 15) The non-transitory computer-readable medium of claim 15, wherein the header further includes data identifying the second next hop, wherein data identifying the first next hop and the data identifying the second next hop is included in the header based on advertising the reachability associated with the first next hop and the second next hop, and wherein the one or more instructions further cause the first device to: determine routing from data identified in the first next hop and the second next hop. ### Claim 19 (depends on 15) The non-transitory computer-readable medium of claim 15, wherein the first segment identifier list is associated with the particular segment routing policy. ### Claim 20 (depends on 15) The non-transitory computer-readable medium of claim 15, wherein the packet is associated with an application of the second device.