# US 11,909,648 B2 · Split-brain prevention in a high availability system during workload migration system during workload migration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,648 B2 - Document ID: US11909648B2 - Status: Granted - Kind: B2 - Application number: 17/582,806 - Filed: 2022-01-24 - Published: 2022-05-12 - Granted: 2024-02-20 - Earliest claimed: 2020-06-04 - Assignees: VMware, Inc. - Applicants: VMware LLC - Inventors: Ankit Parmar; Dileep Devireddy; Subin Cyriac Mathew - Web page: https://patentgrep.com/patent/US11909648B2 ## CPC - H04L 45/22: {Alternate routing} - H04L 45/021: Ensuring consistency of routing table updates, e.g. by using epoch numbers - H04L 45/122: by minimising distances, e.g. by selecting a route with minimum of number of hops - H04L 45/20: {Hop count for routing purposes, e.g. TTL} - H04L 45/28: using route fault recovery - H04L 45/42: Centralised routing - H04L 47/125: by balancing the load, e.g. traffic engineering - H04L 47/762: triggered by the network - H04L 47/781: {Centralised allocation of resources} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In some embodiments, a method configures, at a first host, an overlay channel for sending packets to check whether a failure has occurred at a workload. The first host and a second host are connected via a layer 3 network. The first host generates a packet to check whether the failure has occurred at the workload and encapsulates the packet. The first host sends the encapsulated packet to the second host using the overlay channel via the layer 3 network. The packet is decapsulated and forwarded to the workload at the second host. ## Claims ### Claim 1 A method comprising: configuring, at a first host, an overlay channel for sending packets to check whether a failure has occurred at an active edge services gateway workload at a second host, wherein the first host and a second host are connected via a layer 3 network; generating, at the first host, a packet to check whether the failure has occurred at the active edge services gateway workload at the second host; encapsulating the packet; and sending, from a standby edge services gateway workload on the first host, the encapsulated packet to the active edge services gateway workload on the second host using the overlay channel via the layer 3 network, wherein the packet is decapsulated and forwarded to the active edge services gateway workload at the second host; based on information received from the sending, determining the active edge services gateway workload has failed. ### Claim 2 (depends on 1) The method of claim 1, wherein the active edge services gateway workload is an active edge services gateway device that processes north-south traffic. ### Claim 3 (depends on 1) The method of claim 1, further comprising, based on determining the active edge services gateway workload has failed, switching the standby edge services gateway workload to active. ### Claim 4 (depends on 1) The method of claim 1, further comprising: receiving a control message on a control channel for sending control messages between the first host and the second host, wherein the control message includes a next hop to reach the active edge services gateway workload; and programming a route table with the next hop to reach the active edge services gateway workload. ### Claim 5 (depends on 1) The method of claim 1, wherein: the packet comprises a first packet, the overlay channel is associated a first endpoint and a second endpoint, wherein first endpoint includes a first address and the second endpoint includes a second address; and the first address and the second address do not change due to a migration of the active edge services gateway workload from a third host to the second host. ### Claim 6 (depends on 5) The method of claim 5, further comprising: adding a third address for a next hop for the active edge services gateway workload in the second host in a route table, wherein the route table previously included the next hop of a fourth address to use to reach the active edge services gateway workload on the third host. ### Claim 7 (depends on 1) The method of claim 1, wherein the encapsulated packet comprises a first encapsulated packet and the active edge services gateway workload comprises a first workload, the method further comprising: receiving a second encapsulated packet from the active edge services gateway workload through the overlay channel, wherein the second encapsulated packet is used to determine whether the failure at the workload occurred. ### Claim 8 A non-transitory computer-readable storage medium containing instructions, that when executed, control a computer system to be operable for: configuring, at a first host, an overlay channel for sending packets to check whether a failure has occurred at an active edge services gateway workload on a second host, wherein the first host and a second host are connected via a layer 3 network; generating, at a standby edge services gateway workload on the first host, a packet to check whether the failure has occurred at the active edge services gateway workload on the second host; encapsulating the packet; and sending, from the standby edge services gateway workload on the first host, the encapsulated packet to the active edge services gateway workload on the second host using the overlay channel via the layer 3 network, wherein the packet is decapsulated and forwarded to the active edge services gateway workload at the second host. ### Claim 9 (depends on 8) The non-transitory computer-readable storage medium of claim 8, further operable for: configuring a route table with a next hop for the active edge services gateway workload, wherein the packet is sent to the active edge services gateway workload via the next hop. ### Claim 10 (depends on 8) The non-transitory computer-readable storage medium of claim 8, wherein: the overlay channel includes a first address of a first endpoint and a second address of a second endpoint; and the encapsulated packet is sent via the layer 3 network by routing the encapsulated packet using the second address of the second endpoint. ### Claim 11 (depends on 8) The non-transitory computer-readable storage medium of claim 8, further operable for: receiving a control message on a control channel for sending control messages between the first host and the second host, wherein the control message includes a next hop to reach the active edge services gateway workload; and programming a route table with the next hop to reach the active edge services gateway workload. ### Claim 12 (depends on 8) The non-transitory computer-readable storage medium of claim 8, wherein: the packet comprises a first packet, the overlay channel is associated a first endpoint and a second endpoint, wherein first endpoint includes a first address and the second endpoint includes a second address; and the first address and the second address do not change due to a migration of the active edge services gateway workload from a third host to the second host. ### Claim 13 (depends on 8) The non-transitory computer-readable storage medium of claim 8, wherein the encapsulated packet comprises a first encapsulated packet and the active edge services gateway workload comprises a first workload, the method further comprising: receiving a second encapsulated packet from the active edge services gateway workload through the overlay channel, wherein the second encapsulated packet is used to determine whether the failure at the active edge services gateway workload occurred. ### Claim 14 (depends on 13) The non-transitory computer-readable storage medium of claim 13, further operable for: adding a third address for a next hop for the active edge services gateway workload in the second host in a route table, wherein the route table previously included the next hop of a fourth address to use to reach the active edge services gateway workload on the third host. ### Claim 15 A first host comprising: one or more computer processors; and a non-transitory computer-readable storage medium comprising instructions, that when executed, control the one or more computer processors to be operable for: configuring an overlay channel for sending packets to check whether a failure has occurred at an active edge services gateway workload on a second host, wherein the first host and a second host are connected via a layer 3 network; generating a packet to check whether the failure has occurred at the active edge services gateway workload; encapsulating the packet; and sending, from a standby edge services gateway workload on the first host, the encapsulated packet to the active edge services gateway workload on the second host using the overlay channel via the layer 3 network, wherein the packet is decapsulated and forwarded to the active edge services gateway workload at the second host. ### Claim 16 (depends on 15) The first host of claim 15, further operable for: configuring a route table with a next hop for the active edge services gateway workload, wherein the packet is sent to the active edge services gateway workload via the next hop. ### Claim 17 (depends on 15) The first host of claim 15, wherein: the overlay channel includes a first address of a first endpoint and a second address of a second endpoint; and the encapsulated packet is sent via the layer 3 network by routing the encapsulated packet using the second address of the second endpoint. ### Claim 18 (depends on 15) The first host of claim 15, further operable for: receiving a control message on a control channel for sending control messages between the first host and the second host, wherein the control message includes a next hop to reach the active edge services gateway workload; and programming a route table with the next hop to reach the active edge services gateway workload. ### Claim 19 (depends on 15) The first host of claim 15, wherein: the packet comprises a first packet, the overlay channel is associated a first endpoint and a second endpoint, wherein first endpoint includes a first address and the second endpoint includes a second address; and the first address and the second address do not change due to a migration of the active edge services gateway workload from a third host to the second host. ### Claim 20 (depends on 19) The first host of claim 19, further operable for: adding a third address for a next hop for the active edge services gateway workload in the second host in a route table, wherein the route table previously included the next hop of a fourth address to use to reach the active edge services gateway workload on the third host. ### Claim 21 (depends on 15) The first host of claim 15, wherein the encapsulated packet comprises a first encapsulated packet and the active edge services gateway workload comprises a first workload, the method further comprising: receiving a second encapsulated packet from the active edge services gateway workload through the overlay channel, wherein the second encapsulated packet is used to determine whether the failure at the active edge services gateway workload occurred.