https://github.com/libp2p/go-reuseport

reuse tcp/udp ports in golang
https://github.com/libp2p/go-reuseport

Last synced: 3 months ago
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reuse tcp/udp ports in golang

• Host: GitHub
• URL: https://github.com/libp2p/go-reuseport
• Owner: libp2p
• License: isc
• Created: 2015-01-19T04:23:51.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2025-03-29T08:32:27.000Z (4 months ago)
• Last Synced: 2025-04-23T20:59:49.731Z (3 months ago)
• Language: Go
• Homepage:
• Size: 151 KB
• Stars: 788
• Watchers: 31
• Forks: 110
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# go-reuseport

[![](https://img.shields.io/badge/made%20by-Protocol%20Labs-blue.svg?style=flat-square)](https://protocol.ai)

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[![](https://img.shields.io/badge/project-libp2p-yellow.svg?style=flat-square)](https://libp2p.io/)

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This package enables listening and dialing from _the same_ TCP or UDP port.

This means that the following sockopts may be set:

```

SO_REUSEADDR

SO_REUSEPORT

```

This is a simple package to help with address reuse. This is particularly

important when attempting to do TCP NAT holepunching, which requires a process

to both Listen and Dial on the same TCP port. This package provides some

utilities around enabling this behaviour on various OS.

## Examples

```Go

// listen on the same port. oh yeah.

l1, _ := reuse.Listen("tcp", "127.0.0.1:1234")

l2, _ := reuse.Listen("tcp", "127.0.0.1:1234")

```

```Go

// dial from the same port. oh yeah.

l1, _ := reuse.Listen("tcp", "127.0.0.1:1234")

l2, _ := reuse.Listen("tcp", "127.0.0.1:1235")

c, _ := reuse.Dial("tcp", "127.0.0.1:1234", "127.0.0.1:1235")

```

**Note: cant dial self because tcp/ip stacks use 4-tuples to identify connections, and doing so would clash.**

## Tested

Tested on `darwin`, `linux`, and `windows`.

---

The last gx published version of this module was: 0.2.2: Qme8kdM7thoCqLqd7GYCRqipoZJS64rhJo5MBcTpyWfsL9