# US 12,003,406 B2 · Method and system for network traffic diversion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,406 B2 - Document ID: US12003406B2 - Status: Granted - Kind: B2 - Application number: 17/699,237 - Filed: 2022-03-21 - Published: 2022-06-30 - Granted: 2024-06-04 - Earliest claimed: 2019-11-18 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Patrice Brissette; Luc Andre Burdet; Jiri Chaloupka; Mei Zhang; Tarek Saad - Web page: https://patentgrep.com/patent/US12003406B2 ## CPC - H04L 45/28: using route fault recovery - H04L 45/22: {Alternate routing} - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method, network device, and computer program product for network traffic diversion are disclosed. In one embodiment, a method according to the present disclosure includes receiving a frame at a core edge node that is a member of a redundancy group (where the frame comprises network address information and a packet), and determining whether a link is affected by a network failure. The frame was sourced by a remote core edge node that is not a member of the redundancy group, and the network address information indicates that the packet is to be forwarded via the link. In response to the link being affected by the network failure, the method further includes generating a modified frame and forwarding the modified frame to another core edge node. The generating comprises including a redirect label in the modified frame. The another core edge node is another member of the redundancy group. ## Claims ### Claim 1 A method comprising: receiving a frame at an edge node that is part of a redundancy group; determining whether the frame is a modified frame that includes a redirect label that replaced a direct label in the frame, to modify the frame in response to a link affected by a network failure; and when it is determined that the frame already includes the redirect label, dropping the frame to avoid further redirection of the frame. ### Claim 2 (depends on 1) The method of claim 1, wherein dropping the frame prevents forwarding of the frame that will return to its point of origination. ### Claim 3 (depends on 2) The method of claim 2, wherein when it is determined that the frame is the modified frame that includes the redirect label, dropping of the frame is performed to prevent ping-ponging of a redirected frame between edge nodes. ### Claim 4 (depends on 1) The method of claim 1, wherein determining whether the frame is the modified frame that includes the redirect label comprises determining that a label of the frame is one of one or more redirect labels registered by other nodes in the redundancy group. ### Claim 5 (depends on 1) The method of claim 1, wherein determining whether the frame is the modified frame that includes the redirect label comprises determining that a label of the frame is not a virtual private networking (VPN) label. ### Claim 6 (depends on 1) The method of claim 1, wherein the frame is received from a core node within a core network. ### Claim 7 (depends on 1) The method of claim 1, wherein the redirect label is configured to cause another core edge node to perform forwarding of the frame despite the link via which the frame is to be forwarded being determined to be a non-designated forwarder state. ### Claim 8 (depends on 1) The method of claim 1, further comprising: determining whether the frame comprises another redirect label; and in response to a determination that the frame comprises the another redirect label: determining whether the link over which the frame is received is affected by the network failure, and in response to the link being affected by the network failure, dropping the frame. ### Claim 9 (depends on 1) The method of claim 1, wherein the redirect label is one of a plurality of redirect labels registered by other nodes in the redundancy group. ### Claim 10 A network device comprising: one or more processors; a first network interface, coupled to the one or more processors and configured to be coupled to a link coupled to an access network; a second network interface, coupled to the one or more processors and configured to be coupled to a core network; a computer-readable storage medium, coupled to the one or more processors; and a plurality of instructions, encoded in the computer-readable storage medium and configured to cause the one or more processors to perform operations including: receiving a frame at an edge node that is part of a redundancy group; determining whether the frame is a modified frame that includes a redirect label that replaced a direct label in the frame, to modify the frame in response to a link affected by a network failure; and when it is determined that the frame already includes the redirect label, dropping the frame to avoid further redirection of the frame. ### Claim 11 (depends on 10) The network device of claim 10, wherein dropping the frame prevents forwarding of the frame that will return to its point of origination. ### Claim 12 (depends on 11) The network device of claim 11, wherein when it is determined that the frame is the modified frame that includes the redirect label, dropping of the frame is performed to prevent ping-ponging of a redirected frame between edge nodes. ### Claim 13 (depends on 10) The network device of claim 10, wherein determining whether the frame is the modified frame that includes the redirect label comprises determining that a label of the frame is one of one or more redirect labels registered by other nodes in the redundancy group. ### Claim 14 (depends on 10) The network device of claim 10, wherein determining whether the frame is the modified frame that includes the redirect label comprises determining that a label of the frame is not a virtual private networking (VPN) label. ### Claim 15 (depends on 10) The network device of claim 10, wherein the frame is received from a core node within the core network. ### Claim 16 A non-transitory computer-readable storage medium encoded with instructions that, when executed by one or more processors of an edge node, cause the one or more processors to perform operations including: receiving a frame at an edge node that is part of a redundancy group; determining whether the frame is a modified frame that includes a redirect label that replaced a direct label in the frame, to modify the frame in response to a link affected by a network failure; and when it is determined that the frame already includes the redirect label, dropping the frame to avoid further redirection of the frame. ### Claim 17 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein dropping the frame prevents forwarding of the frame that will return to its point of origination. ### Claim 18 (depends on 17) The non-transitory computer-readable storage medium of claim 17, wherein when it is determined that the frame already includes the redirect label, dropping of the frame is performed to prevent ping-ponging of a redirected frame between edge nodes. ### Claim 19 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein determining whether the frame already includes the redirect label comprises determining that a label of the frame is one of one or more redirect labels registered by other nodes in the redundancy group. ### Claim 20 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein determining whether the frame already includes the redirect label comprises determining that a label of the frame is not a virtual private networking (VPN) label.