# US 2019/0173777 A1 · Virtual port channel bounce in overlay network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0173777 A1 - Document ID: US20190173777A1 - Status: Published application - Kind: A1 - Application number: 16/268,409 - Filed: 2019-02-05 - Published: 2019-06-06 - Earliest claimed: 2013-11-05 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Kit Chiu Chu; Thomas J. Edsall; Navindra Yadav; Francisco M. Matus; Krishna Doddapaneni; Satyam Sinha - Web page: https://patentgrep.com/patent/US20190173777A1 ## CPC - H04L 45/28: using route fault recovery - H04L 12/18: for broadcast or conference {, e.g. multicast} - H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling} - H04L 12/4641: {Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272)} - H04L 12/4645: {Details on frame tagging (routing of packets H04L45/00; support for virtual LAN H04L49/354)} - H04L 41/0654: using network fault recovery (ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437) - H04L 43/0811: by checking connectivity - H04L 43/0852: Delays - H04L 43/0894: Packet rate - H04L 43/16: Threshold monitoring - H04L 45/021: Ensuring consistency of routing table updates, e.g. by using epoch numbers - H04L 45/16: Multipoint routing - H04L 45/24: Multipath - H04L 45/245: {Link aggregation, e.g. trunking} - H04L 45/48: Routing tree calculation - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L 45/74: Address processing for routing - H04L 45/745: Address table lookup; Address filtering - H04L 45/7453: using hashing - H04L 49/70: {Virtual switches} - H04L 51/214: using selective forwarding - H04L 61/2503: Translation of Internet protocol [IP] addresses - H04L 61/2592: using tunnelling or encapsulation - H04L 67/10: in which an application is distributed across nodes in the network (software deployment G06F8/60; multiprogramming arrangements G06F9/46) - H04L 69/22: Parsing or analysis of headers - H04L 45/64: using an overlay routing layer - H04L 47/125: by balancing the load, e.g. traffic engineering - H04L 2212/00: Encapsulation of packets - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Aspects of the subject disclosure relate to methods for detecting a link failure between the first network device and a destination node, receiving a data packet addressed to the destination node, and rewriting encapsulation information of the first data packet. Subsequent to rewriting the encapsulation information of the first data packet, the first data packet is forwarded to a second network device (e.g., using updated address information in the packet header), wherein the second network device is paired with the first network device in the virtual port channel. In certain aspects, systems and computer readable media are also provided. ## Claims ### Claim 1 A computer-implemented method comprising: detecting, by a first network device in a virtual port channel, a link failure between the first network device and a destination node; sending, by the first network device, a data packet to a second network device based on detection of the link failure, the second network device paired with the first network device in the virtual port channel; receiving, by the second network device, the data packet; and forwarding or discarding the data packet, by the second network device, based on an indication of a prior packet bounce of the data packet. ### Claim 2 (depends on 1) The computer-implemented method of claim 1, wherein the data packet is forwarded and the forwarding includes updating encapsulation information of the data packet to include an address of the second network device. ### Claim 3 (depends on 2) The computer-implemented method of claim 2, wherein the updating of the encapsulation information includes transmitting the first data packet to the second network device for forwarding to the destination node. ### Claim 4 (depends on 2) The computer-implemented method of claim 2, wherein the updating of the encapsulation information includes modifying an outer tunnel-end-point (TEP) destination address of the data packet. ### Claim 5 (depends on 1) The computer-implemented method of claim 1, wherein the indication is that the data packet was undeliverable by the destination node. ### Claim 6 (depends on 5) The computer-implemented method of claim 5, wherein the data packet is discarded by the second network device based on the indication. ### Claim 7 (depends on 1) The computer-implemented method of claim 1, wherein the first network device is configured to retain an address of the second network device and a shared address of the virtual port channel. ### Claim 8 (depends on 1) The computer-implemented method of claim 1, wherein the virtual port channel comprises a third network device, the third network device and the second network device each being connected to a second destination node, and wherein a forwarding decision for a second data packet addressed to the second destination node is made by the second network device and the first network device based on a hash function performed on address information of the second data packet. ### Claim 9 A system comprising: a first network device and a second network device, each comprising one or more processors and a computer-readable medium comprising instructions stored therein, which when executed by the processors, cause the one or more processors to perform operations comprising: detecting, by the first network device in a virtual port channel, a link failure between the first network device and a destination node; sending, by the first network device, a data packet to the second network device based on detection of the link failure, the second network device paired with the first network device in the virtual port channel; receiving, by the second network device, the data packet; and forwarding or discarding the data packet, by the second network device, based on an indication of a prior packet bounce of the data packet. ### Claim 10 (depends on 9) The system claim 9, wherein the indication is a flipped bit. ### Claim 11 (depends on 9) The system claim 9, the data packet is forwarded and the forwarding includes modifying an outer tunnel-end-point (TEP) destination address of the data packet. ### Claim 12 (depends on 9) The system claim 9, wherein the indication is that the data packet was undeliverable by the destination node. ### Claim 13 (depends on 12) The system of claim 12, wherein the data packet is discarded by the second network device based on the indication that the data packet was undeliverable by the destination node. ### Claim 14 (depends on 9) The system of claim 9, wherein the one or more processors are further configured to perform operations comprising: storing, at the first network device, an address of the second network device and a shared address of the virtual port channel. ### Claim 15 (depends on 9) The system of claim 9, wherein the virtual port channel comprises a third network device, the third network device and the second network device each being connected to a second destination node, and wherein a forwarding decision for a second data packet addressed to the second destination node is made by the second network device and the first network device based on a hash function performed on address information of the second data packet. ### Claim 16 A non-transitory computer-readable storage medium comprising instructions stored therein, which when executed by one or more processors, cause the processors to perform operations comprising: detecting, by a first network device in a virtual port channel, a link failure between the first network device and a destination node; sending, by the first network device, a data packet to a second network device based on detection of the link failure, the second network device paired with the first network device in the virtual port channel; receiving, by the second network device, the data packet; and forwarding or discarding the data packet, by the second network device, based on an indication of a prior packet bounce of the data packet. ### Claim 17 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein the data packet is forwarded and the forwarding includes updating encapsulation information of the data packet to include an address of the second network device. ### Claim 18 (depends on 17) The non-transitory computer-readable storage medium of claim 17, wherein updating the encapsulation information includes transmitting the first data packet to the second network device for forwarding to the destination node. ### Claim 19 (depends on 18) The non-transitory computer-readable storage medium of claim 18, wherein the first network device is configured to retain the address of the second network device and a shared address of the virtual port channel. ### Claim 20 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein the indication is that the data packet was undeliverable by the destination node.