# US 12,184,532 B1 · Using anycast as an abstract next hop (ANH) to reduce information related to border gateway protocol (BGP) next hops received by autonomous system border routers (ASBRs) and/or to improve BGP path convergence > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,532 B1 - Document ID: US12184532B1 - Status: Granted - Kind: B1 - Application number: 18/381,607 - Filed: 2023-10-18 - Granted: 2024-12-31 - Earliest claimed: 2020-08-17 - Assignees: Juniper Networks, Inc. - Applicants: Juniper Networks, Inc. - Inventors: Suraj Narayan Sharma; Hitesh Mali - Web page: https://patentgrep.com/patent/US12184532B1 ## CPC - H04L 45/04: {Interdomain routing, e.g. hierarchical routing} - H04L 45/033: by updating distance vector protocols - H04L 61/5069: for group communication, multicast communication or broadcast communication - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An autonomous system border router (ASBR) provided in a domain in which routers share an anycast address, may perform a method comprising: (a) receiving, from an exterior Border Gateway Protocol (eBGP) peer, first reachability information for a first prefix, the first reachability information including a first next hop (NH) address; (b) communicating first link state information about the first prefix to another router in the domain, the first link state information associating the first prefix with the anycast address; (c) receiving, from an eBGP peer, second reachability information for a second prefix, the second reachability information including a second next hop (NH) address; and (d) communicating second link state information about the second prefix to the other router in the domain, the second link state information associating the second prefix with the anycast address. This effectively reduces the number of next hops related to a prefix learned by two or more ASBRs (e.g., one or more spine routers in a Clos of an aggregate spine) via eBGP, stored as forwarding information on a non-ASBR in an IGP domain (e.g., on a leaf node in a Clos of an aggregate spine). ## Claims ### Claim 1 A router provided in a first domain in which routers share a first anycast address, the router comprising: a) a control component; and b) a packet forwarding component including a storage device storing forwarding information including (1) a first prefix associated with the first anycast address, the first anycast address provided as an abstract next hop for the first prefix, in association with a loopback address of a first autonomous system border router (ASBR) in the first domain, and (2) a second prefix associated with the first anycast address, the first anycast address provided as an abstract next hop for the second prefix, in association with a loopback address of the first ASBR. ### Claim 2 (depends on 1) The router of claim 1, wherein the forwarding information further includes (3) the first prefix associated with the first anycast address, the first anycast address provided as an abstract next hop for the first prefix, in association with a loopback address of a second autonomous system border router (ASBR) in the first domain. ### Claim 3 (depends on 2) The router of claim 2, wherein the loopback address of the first ASBR and the loopback address of the second ASBR are associated with the first anycast address as equal cost multipaths (ECMPs) for the first prefix. ### Claim 4 (depends on 2) The router of claim 2, wherein the forwarding information further includes (4) the second prefix associated with the first anycast address, the first anycast address provided as an abstract next hop for the second prefix, in association with a loopback address of the second ASBR. ### Claim 5 (depends on 4) The router of claim 4, wherein the loopback address of the first ASBR and the loopback address of the second ASBR are associated with the first anycast address as equal cost multipaths (ECMPs) for the second prefix. ### Claim 6 (depends on 1) The router of claim 1, wherein the router is a leaf node in a CLOS network, wherein the first ASBR is a first spine node in the CLOS network, wherein the second ASBR is a second spine node in the CLOS network, and wherein the first anycast address is associated with the CLOS network. ### Claim 7 (depends on 1) The router of claim 1, wherein the router is a leaf node in a CLOS network, and wherein the first anycast address is associated with the CLOS network. ### Claim 8 (depends on 1) The router of claim 1 wherein the packet forwarding component further includes a packet forwarding circuitry configured such that, responsive to receiving a packet destined for one of the first prefix and the second prefix, the packet forwarding circuitry forwards the packet received to the one of the first prefix and the second prefix using the stored forwarding information. ### Claim 9 A router provided in a first domain in which routers share a first anycast address, the router comprising: a) a control component; and b) a packet forwarding component including a storage device storing forwarding information including (1) a first prefix associated with both the first anycast address, the first anycast address provided as an abstract next hop for the first prefix in a primary route, in association with a loopback address of a first autonomous system border router (ASBR) in the first domain, and a second anycast address, the second anycast address provided as an abstract next hop for the first prefix in a secondary route, in association with a loopback address of a second ASBR and (3) a second prefix associated with both the first anycast address, the first anycast address provided as an abstract next hop for the second prefix in a primary route, in association with a loopback address of the first ASBR, and the second anycast address, the second anycast address provided as an abstract next hop for the second prefix in a secondary route, in association with the loopback address of the second ASBR. ### Claim 10 (depends on 9) The router of claim 9, wherein the router is a leaf node in a first CLOS network. ### Claim 11 (depends on 10) The router of claim 10, wherein the first ASBR is a spine node in the first CLOS network, and wherein the first anycast address is associated with the first CLOS network. ### Claim 12 (depends on 11) The router of claim 11, wherein the second ASBR is a spine node in a second CLOS network, and wherein the second anycast address is associated with the second CLOS network. ### Claim 13 (depends on 12) The router of claim 12, wherein the first CLOS network and the second CLOS network are linked via a ring routers. ### Claim 14 (depends on 12) The router of claim 12, wherein the first CLOS network and the second CLOS network belong to a common interior gateway protocol (IGP) domain.