# US 11,909,717 B1 · Duplicate address detection for ranges of global IP addresses

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,909,717 B1
- Document ID: US11909717B1
- Status: Granted
- Kind: B1
- Application number: 18/166,954
- Filed: 2023-02-09
- Granted: 2024-02-20
- Earliest claimed: 2019-04-03
- Assignees: Juniper Networks, Inc.
- Applicants: Juniper Networks, Inc.
- Inventors: Manoj Nayak; Rafik Puttur
- Web page: https://patentgrep.com/patent/US11909717B1

## CPC

- H04L 61/5007: Internet protocol [IP] addresses
- H04L 45/74: Address processing for routing
- H04L 61/5092: by self-assignment, e.g. picking addresses at random and testing if they are already in use
- H04L 2101/659: Internet protocol version 6 [IPv6] addresses
- H04L 2101/668: Internet protocol [IP] address subnets
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

An example network device determines to assign a number of global Internet protocol (IP) addresses to respective network interfaces, determines a subnetwork for the network interfaces, determines a prefix corresponding to the subnetwork, determines a first global IP address having the prefix, determines a range value that is equal to or greater than the number of global IP addresses, generates a message according to Duplicate Address Detection Protocol (DAD) including data indicating that the message includes a range of addresses, the data further indicating the first global IP address and the range value, and sends the message according to DAD to one or more host network devices to determine whether any global IP address in a range starting with the first global IP address and through the range value is in use by the one or more host network devices.

## Claims

### Claim 1

A host network system comprising:
a network interface implemented in circuitry; and
one or more processors implemented in circuitry and configured to:
receive a first message according to Duplicate Address Detection Protocol (DAD) from a first local network device, the first message including data indicating that the first message includes a first range of global Internet protocol (IP) addresses, the data further indicating a first ordinal first global IP address in the first range and a first range value;
determine that at least one global IP address in the first range of global IP addresses starting with the first ordinal first global IP address and through the first range value is reserved by the host network system;
send, via the network interface, a response message representative of the at least one global IP address;
receive a second message according to DAD from a second local network device, the second message including data indicating that the second message includes a second range of global IP addresses, the data further indicating a second ordinal first global IP address in the second range and a second range value;
determine that no global IP addresses in the second range of global IP addresses are reserved by the host network system; and
in response to determining that no global IP addresses in the second range of global IP addresses are reserved by the host network system, ignore the second message.

### Claim 2 (depends on 1)

The host network system of claim 1, wherein to send the response message, the one or more processors are configured to send a neighbor advertisement message specifying that the at least one global IP address is reserved.

### Claim 3 (depends on 2)

The host network system of claim 2, wherein the one or more processors are configured to send the neighbor advertisement message to the first local network device.

### Claim 4 (depends on 1)

The host network system of claim 1, wherein the one or more processors are further configured to determine whether to retain reservation of the at least one global IP address.

### Claim 5 (depends on 1)

The host network system of claim 1, wherein the one or more processors are further configured to determine to release reservation of the at least one global IP address, wherein to send the response message, the one or more processors are configured to send one or more neighbor advertisement messages, including the response message, to one or more other host network devices indicating that the host network system is releasing reservation of the at least one global IP address.