# US 12,224,930 B2 · Establishment of method and apparatus for implementing entry backup > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,930 B2 - Document ID: US12224930B2 - Status: Granted - Kind: B2 - Application number: 17/562,101 - Filed: 2021-12-27 - Published: 2022-04-21 - Granted: 2025-02-11 - Earliest claimed: 2019-06-28 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Jun Liu; Yaokun Zhang - Web page: https://patentgrep.com/patent/US12224930B2 ## CPC - H04L 67/1095: Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes - H04L 12/4625: {Single bridge functionality, e.g. connection of two networks over a single bridge} - 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 45/033: by updating distance vector protocols - H04L 45/04: {Interdomain routing, e.g. hierarchical routing} - H04L 45/22: {Alternate routing} - H04L 45/28: using route fault recovery - H04L 45/42: Centralised routing - H04L 45/66: {Layer 2 routing, e.g. in Ethernet based MAN's} - H04L 45/247: using M:N active or standby paths - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L 47/125: by balancing the load, e.g. traffic engineering - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract This application discloses a method and apparatus for implementing entry backup. When a first network device needs to back up information about a first entry stored in the first network device to a second network device, the first network device generates a first BGP message that includes first entry information, and sends the first BGP message to the second network device, where the first BGP message is used to advertise a newly defined entry backup route to the second network device, or the first BGP message includes an extended community attribute. After receiving the first BGP message, the second network device may obtain a second entry based on the first BGP message, and store information about the second entry, where the second entry is a backup entry of the first entry. ## Claims ### Claim 1 A method for implementing entry backup, comprising: generating, by a first network device, a first border gateway protocol (BGP) message, wherein the first BGP message comprises first entry information, and the first entry information comprises information about a first entry stored in the first network device; and sending, by the first network device, the first BGP message to a second network device, wherein the first BGP message advertises an entry backup route to the second network device to enable the second network device to obtain a second entry based on the first BGP message, wherein information about the second entry comprises the first entry information, and the second entry is a backup entry of the first entry, wherein the first BGP message comprises a route type field, and the route type field indicates that a type of a route advertised by the first BGP message is the entry backup route. ### Claim 2 (depends on 1) The method according to claim 1, wherein the first BGP message comprises Ethernet virtual private network network layer reachability information (EVPN NLRI), the EVPN NLRI carries an Ethernet segment identifier (ESI). ### Claim 3 (depends on 1) The method according to claim 1, wherein the first BGP message comprises first network layer reachability information (NLRI), and a subsequent address family identifier (SAFI), the SAFI indicates that an address family of the first BGP message is a BGP backup address family, and the first NLRI carries a backup interface identifier (backup_id). ### Claim 4 (depends on 1) The method according to claim 1, further comprising: sending, by the first network device, a second BGP message to the second network device, wherein the second BGP message advertises a route for withdrawing the backup entry and indicates the second network device to delete the second entry. ### Claim 5 (depends on 1) The method according to claim 1, further comprising: sending, by the first network device to a third network device, a fourth BGP message comprising the first entry information to enable the third network device to obtain a third entry based on the fourth BGP message, wherein information about the third entry comprises the first entry information, and the third entry is a backup entry of the first entry. ### Claim 6 (depends on 1) The method according to claim 1, wherein the first entry is an address resolution protocol (ARP) entry, a neighbor discovery protocol (NDP) entry, an internet group management protocol (IGMP) entry, an internet group management protocol snooping (IGMP SNP) entry, a dynamic host configuration protocol snooping (DHCP SNP) entry, or a broadband access server (BAS) entry. ### Claim 7 A second network device, comprises a memory and a processor, wherein the memory is configured to store program code; and the processor is configured to run instructions in the program code, to cause the second network device to perform operations comprising: receiving a first BGP message sent by a first network device, wherein the first BGP message comprises first entry information, and the first entry information comprises information about a first entry stored in the first network device; and obtaining a second entry based on the first BGP message and storing information about the second entry, wherein the second entry is a backup entry of the first entry, and the information about the second entry comprises the first entry information, wherein the first BGP message comprises a route type field, and the route type field indicates that a type of a route advertised by the first BGP message is an entry backup route. ### Claim 8 (depends on 7) The second network device according to claim 7, wherein the first BGP message carries an Ethernet segment identifier (ESI) and the operations further comprise: obtaining port information based on the ESI, wherein the second entry comprises the port information. ### Claim 9 (depends on 7) The second network device according to claim 7, wherein the first BGP message comprises first network layer reachability information (NLRI), and a subsequent address family identifier (SAFI), wherein the SAFI indicates that an address family of the first BGP message is a BGP backup address family, and the first NLRI carries a backup interface identifier (backup_id), and the operations further comprise: obtaining port information based on the backup_id, wherein the second entry comprises the port information. ### Claim 10 (depends on 7) The second network device according to claim 7, wherein the operations further comprise: receiving a second BGP message sent by the first network device, wherein the second BGP message advertises a route for withdrawing the backup entry to the second network device; and deleting the second entry based on the second BGP message. ### Claim 11 (depends on 7) The second network device according to claim 7, wherein the first entry is an address resolution protocol (ARP) entry, a neighbor discovery protocol (NDP) entry, an internet group management protocol (IGMP) entry, an internet group management protocol snooping (IGMP SNP) entry, a dynamic host configuration protocol snooping (DHCP SNP) entry, or a broadband access server (BAS) entry. ### Claim 12 A first network device comprising a memory and a processor, wherein the memory is configured to store program code; and the processor is configured to run instructions in the program code, to cause the first network device to perform operations comprising: generating a first border gateway protocol (BGP) message, wherein the first BGP message comprises first entry information, and the first entry information comprises information about a first entry stored in the first network device, and wherein the first BGP message comprises a route type field, and the route type field indicates that a type of a route advertised by the first BGP message is the entry backup route; and sending the first BGP message to a second network device, wherein the first BGP message advertises an entry backup route to the second network device to enable the second network device to obtain a second entry based on the first BGP message, wherein information about the second entry comprises the first entry information, and the second entry is a backup entry of the first entry. ### Claim 13 (depends on 12) The first network device according to claim 12, wherein the first BGP message comprises Ethernet virtual private network network layer reachability information (EVPN NLRI), the EVPN NLRI carries an Ethernet segment identifier (ESI). ### Claim 14 (depends on 12) The first network device according to claim 12, wherein the first BGP message comprises first network layer reachability information (NLRI) and a subsequent address family identifier (SAFI), the SAFI indicates that an address family of the first BGP message is a BGP backup address family, and the first NLRI carries a backup interface identifier (backup_id). ### Claim 15 (depends on 12) The first network device according to claim 12, wherein the operations further comprise: sending a second BGP message to the second network device, wherein the second BGP message advertises a route for withdrawing the backup entry and indicates the second network device to delete the second entry. ### Claim 16 (depends on 12) The first network device according to claim 12, wherein the operations further comprise: sending, to a third network device, a fourth BGP message comprising the first entry information to enable the third network device to obtain a third entry based on the fourth BGP message, wherein information about the third entry comprises the first entry information, and the third entry is a backup entry of the first entry. ### Claim 17 (depends on 12) The device according to claim 12, wherein the first entry is an address resolution protocol (ARP) entry, a neighbor discovery protocol (NDP) entry, an internet group management protocol (IGMP) entry, an internet group management protocol snooping (IGMP SNP) entry, a dynamic host configuration protocol snooping (DHCP SNP) entry, or a broadband access server (BAS) entry.