# US 11,115,342 B2 · Using BFD packets in a virtualized device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,342 B2 - Document ID: US11115342B2 - Status: Granted - Kind: B2 - Application number: 16/385,046 - Filed: 2019-04-16 - Published: 2020-10-22 - Granted: 2021-09-07 - Earliest claimed: 2019-04-16 - Assignees: Hewlett Packard Enterprise Development LP - Applicants: Hewlett Packard Enterprise Development LP - Inventors: David Corrales Lopez; Agustin Jose Meneses Fuentes; Vivek Ramamoorthy - Web page: https://patentgrep.com/patent/US11115342B2 ## CPC - H04L 41/0893: Assignment of logical groups to network elements - H04L 7/0008: {Synchronisation information channels, e.g. clock distribution lines} - 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 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 41/0668: by dynamic selection of recovery network elements, e.g. replacement by the most appropriate element after failure - H04L 41/0895: Configuration of virtualised networks or elements, e.g. virtualised network function or OpenFlow elements - H04L 41/40: using virtualisation of network functions or resources, e.g. SDN or NFV entities - H04L 45/245: {Link aggregation, e.g. trunking} - H04L 45/28: using route fault recovery - H04L 47/286: {Time to live} - H04L 47/32: by discarding or delaying data units, e.g. packets or frames - H04L 45/20: {Hop count for routing purposes, e.g. TTL} - Y02D 30/50: in wire-line communication networks, e.g. low power modes or reduced link rate - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract Examples disclosed herein relate to a method comprising receiving a bidirectional forwarding detection (BFD) packet originating from a first network device, wherein the first linked network device and a second linked network device are part of a link aggregation group running a BFD session. The method may include transmitting, from the first linked network device, a BFD synchronization packet to the second linked network device and receiving, at the second linked network device, the BFD synchronization packet, wherein a time-to-live (TTL) value of the BFD synchronization packet is lower than a BFD TTL supported by the BFD session. The method may also include determining that the BFD synchronization packet is a BFD single-hop packet coming from a VLANs using the active forwarding mode and determining not to discard the BFD synchronization packet. ## Claims ### Claim 1 A method comprising: receiving, at a first linked network device, a bidirectional forwarding detection (BFD) packet originating from a first network device, wherein the first linked network device and a second linked network device are part of a link aggregation group running a BFD session; transmitting, from the first linked network device, a BFD synchronization packet to the second linked network device, wherein the link aggregation group uses an active forwarding mode where data traffic flowing through first linked network device is routed through the second linked network device; receiving, at the second linked network device, the BFD synchronization packet, wherein a time-to-live (TTL) value of the BFD synchronization packet is lower than a BFD TTL supported by the BFD session; determining, by the second linked network device, that the BFD synchronization packet is a BFD single-hop packet coming from a VLANs using the active forwarding mode; and determining, by the second linked network device, not to discard the BFD synchronization packet. ### Claim 2 (depends on 1) The method of claim 1 comprising: determining, by the second linked network device, that the time-to-live (TTL) value of the BFD synchronization packet is an acceptable increment lower than a BFD TTL supported by the BFD process. ### Claim 3 (depends on 1) The method of claim 1, wherein the BFD session is run on top of the link aggregation group. ### Claim 4 (depends on 1) The method of claim 1, wherein routing data through the second linked network device as part of the active forwarding mode includes decrementing the TTL value by a particular value. ### Claim 5 (depends on 1) The method of claim 1 comprising: establishing a BFD session between the first network device and the link aggregation group. ### Claim 6 (depends on 1) The method of claim 1, wherein the link aggregation group implements asynchronous BFD traffic at a control plane of one or more network devices. ### Claim 7 (depends on 1) The method of claim 1, wherein the link aggregation group has a primary link to the first network device and a secondary link to the first network device. ### Claim 8 (depends on 7) The method of claim 7, wherein the primary link is between the first network device and first linked network device of the link aggregation group and the secondary link is between the first network device and the second linked network device of the link aggregation group. ### Claim 9 A non-transitory computer-readable storage medium encoded with instructions, the instructions executable by a processor of a system to cause the system to: receive, at a second linked network device, a bidirectional forwarding detection (BFD) synchronization packet from a first linked network device, wherein the first linked network device and the second linked network device are part of a link aggregation group running a BFD process and wherein the link aggregation group uses an active forwarding mode where data traffic flowing through first linked network device is routed through the second linked network device; determine, at the second linked network device, that the BFD synchronization packet is a BFD single-hop packet coming from a VLANs using the active forwarding mode and a time-to-live (TTL) value of the BFD synchronization packet is an acceptable increment lower than a BFD TTL supported by the BFD process; and determine, at the second linked network device, not to discard the BFD synchronization packet. ### Claim 10 (depends on 9) The non-transitory computer-readable storage medium of claim 9, the instructions executable by a processor of a system to cause the system to: determine, by the second linked network device, that the time-to-live (TTL) value of the BFD synchronization packet is an acceptable increment lower than a BFD TTL supported by the BFD process. ### Claim 11 (depends on 9) The non-transitory computer-readable storage medium of claim 9, wherein the BFD session is run on top of the link aggregation group. ### Claim 12 (depends on 9) The non-transitory computer-readable storage medium of claim 9, wherein routing data through the second linked network device as part of the active forwarding mode includes decrementing the TTL value by a particular value. ### Claim 13 (depends on 9) The non-transitory computer-readable storage medium of claim 9, wherein the link aggregation group implements asynchronous BFD traffic at a control plane of one or more network devices. ### Claim 14 (depends on 9) The non-transitory computer-readable storage medium of claim 9, wherein the link aggregation group has a primary link is between the first network device and first linked network device of the link aggregation group and a secondary link between the first network device and the second linked network device of the link aggregation group. ### Claim 15 A system comprising: a first BFD packet receiver to receive a bidirectional forwarding detection (BFD) packet originating from a first network device, wherein a first linked network device and a second linked network device are part of a link aggregation group running a BFD process; a BFD packet transmitter to transmit a BFD synchronization packet from the first linked network device, wherein the link aggregation group uses an active forwarding mode where data traffic flowing through first linked network device is routed through the second linked network device; a second BFD receiver to receive the BFD synchronization packet at the second linked network device, wherein a time-to-live (TTL) value of the BFD synchronization packet is lower than a BFD TTL supported by the BFD process; a BFD packet determiner that the BFD synchronization packet is a BFD single-hop packet coming from a VLANs using the active forwarding mode; and a BFD packet adjuster to adjust the time-to-live (TTL) value of the BFD synchronization packet to a BFD TTL supported by the BFD process. ### Claim 16 (depends on 15) The system of claim 15 comprising: the BFD packet determiner to determine that the time-to-live (TTL) value of the BFD synchronization packet is an acceptable increment lower than a BFD TTL supported by the BFD process. ### Claim 17 (depends on 15) The system of claim 15, wherein the BFD session is run on top of the link aggregation group. ### Claim 18 (depends on 15) The system of claim 15, wherein routing data through the second linked network device as part of the active forwarding mode includes decrementing the TTL value by a particular value. ### Claim 19 (depends on 15) The system of claim 15, wherein the link aggregation group implements asynchronous BFD traffic at a forwarding plane of one or more network devices. ### Claim 20 (depends on 15) The system of claim 15, wherein the primary link is between the first network device and first linked network device of the link aggregation group and the secondary link is between the first network device and the second linked network device of the link aggregation group.