# US 10,454,817 B2 · Method and device for processing GR of openflow switch, and openflow controller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,454,817 B2 - Document ID: US10454817B2 - Status: Granted - Kind: B2 - Application number: 15/120,388 - Filed: 2014-07-22 - Published: 2017-03-09 - Granted: 2019-10-22 - Earliest claimed: 2014-02-21 - Assignees: Zte Corporation - Applicants: ZTE Corporation - Inventors: Min Xiao; Liang Fan; Ran Chen - Web page: https://patentgrep.com/patent/US10454817B2 ## CPC - H04L 45/38: {Flow based routing} - H04L 12/6418: {Hybrid transport} - H04L 45/021: Ensuring consistency of routing table updates, e.g. by using epoch numbers - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Provided are a method and device for processing a Graceful Restart (GR) of an OpenFlow switch, and an OpenFlow controller. The method includes that: the OpenFlow switch is determined being in a GR state; and the state of the OpenFlow switch is marked as the GR state, wherein marking the state as the GR state includes: keeping a flow table and external connection of the OpenFlow switch before GR still valid, and prohibiting the flow table from being modified. Through the present disclosure, the problem in the related art that GR of an OpenFlow switch cannot be achieved is solved, thereby achieving the effect of effectively implementing the GR of the OpenFlow switch. ## Claims ### Claim 1 A method for processing a Graceful Restart (GR) of an OpenFlow switch, comprising: determining, by an OpenFlow controller, the OpenFlow switch being in a GR state; and marking, by the OpenFlow controller, a state of the OpenFlow switch as the GR state, wherein marking the state as the GR state comprises: keeping a flow table and external connection of the OpenFlow switch before the GR still valid, and prohibiting the flow table from being modified; wherein determining, by the OpenFlow controller, the OpenFlow switch being in the GR state comprises: sending, by the OpenFlow controller, when connecting with the OpenFlow switch, to the OpenFlow switch a message for inquiring whether the OpenFlow switch supports a capability of the GR; receiving, by the OpenFlow controller, a GR supporting capability response message fed back by the OpenFlow switch; and determining, by the OpenFlow controller, when disconnecting from the OpenFlow switch, the OpenFlow switch being in the GR state according to the received GR supporting capability response message; wherein after marking, by the OpenFlow controller, the state of the OpenFlow switch as the GR state, further comprising: detecting, by the OpenFlow controller, a re-connection with the OpenFlow switch; and clearing, by the OpenFlow controller, the GR state of the OpenFlow switch. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein after marking, by the OpenFlow controller, the state of the OpenFlow switch as the GR state, further comprising: feeding back, by the OpenFlow controller, the GR state of the OpenFlow switch to a network application program module requiring to know a network topology. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein after clearing, by the OpenFlow controller, the GR state of the OpenFlow switch, further comprising: feeding back, by the OpenFlow controller, an updated state obtained after clearing the GR state of the OpenFlow switch to the network application program module requiring to know the network topology. ### Claim 4 A device for processing a Graceful Restart (GR) of an OpenFlow switch, comprising: a hardware processor, configured to perform programming components stored in a memory, wherein the programming components comprise: a determination component, configured to determine the OpenFlow switch being in a GR state; and a marking component, configured to mark the state of the OpenFlow switch as the GR state, wherein marking the state as the GR state comprises: keeping a flow table and external connection of the OpenFlow switch before the GR still valid, and prohibiting the flow table from being modified; wherein the determination component comprises: a sending element, configured to send, when connecting with the OpenFlow switch, to the OpenFlow switch a message for inquiring whether the OpenFlow switch supports a capability of the GR; a second receiving element, configured to receive a GR supporting capability response message fed back by the OpenFlow switch; and a second determination element, configured to determine, when disconnecting from the OpenFlow switch, the OpenFlow switch being in the GR state according to the received GR supporting capability response message; wherein the programming components further comprise: a detection component, configured to detect re-connection with the OpenFlow switch; and a clearing component, configured to clear the GR state of the OpenFlow switch. ### Claim 5 (depends on 4) The device as claimed in claim 4, wherein the programming components further comprise: a first feedback component, configured to feed back the GR state of the OpenFlow switch to a network application program module requiring to know a network topology. ### Claim 6 (depends on 5) An OpenFlow controller, comprising the device as claimed in claim 5. ### Claim 7 (depends on 4) The device as claimed in claim 4, wherein the programming components further comprise: a second feedback component, configured to feed back an updated state obtained after clearing the GR state of the OpenFlow switch to the network application program module requiring to know the network topology. ### Claim 8 (depends on 7) An OpenFlow controller, comprising the device as claimed in claim 7. ### Claim 9 (depends on 4) An OpenFlow controller, comprising the device as claimed in claim 4.