Install ip_relay with Homebrew

Project links

• Homepage
• Upstream docs
• Package manager page

Commands and aliases

• ip_relay

Project history

The project page says ip_relay grew out of Stewart's modem Internet use, where a large download could make interactive activities such as telnet, web browsing, or voice traffic unpleasant. The README dates the documented release line to 2000-01-05 and describes the program as a TCP relay with traffic-shaping behavior.

Version 0.71, announced on 2000-05-27, added daemon mode and a command-line bandwidth option. The changelog attributes the daemon-mode request to Eduardo Augusto Alvarenga and notes command-line bandwidth selection as the other release change.

Adoption history

The official site preserves only a small release archive, and Homebrew packaging gives the tool most of its package-manager visibility. That makes it a niche package rather than a broadly adopted network daemon.

Its adoption story is strongest as preserved Unix networking craft: a small Perl program kept installable for users who want an inspectable TCP proxy to reproduce old bandwidth conditions or throttle a few streams.

How it is used

The common pattern is `ip_relay.pl local_port:remote_host:remote_port`, then optionally setting a total byte-per-second bandwidth cap shared by forwarded streams. The README walks through using it as an SSH or proxy relay and changing the bandwidth interactively while traffic flows.

The FAQ is explicit about the tradeoffs: ip_relay is not authenticated, not secure, not designed for multiple users, and single-threaded. It is best understood as a local testing and personal bandwidth-shaping tool.

Why package nerds care

ip_relay is interesting to package nerds because it captures a pre-broadband style of Unix utility: a short Perl program solving a concrete modem-era problem with almost no infrastructure.

Its Homebrew formula keeps a tiny historical networking tool available without pretending it is a modern traffic-control framework.

Timeline

• 1999: The README examples identify the program as copyright Gavin Stewart 1999.
• 2000-01-05: README date for the documented ip_relay.pl release line.
• 2000-05-27: Version 0.71 announced with daemon mode and command-line bandwidth selection.
• 2000: Older revision 0.7 and release 0.71 preserved on the project site.
• Homebrew era: The tool was packaged as `ip_relay` for one-command installation.

Related projects

• Conceptually related tools include SOCKS proxies, local HTTP proxy setups, traffic-shaping routers, and operating-system traffic-control facilities, but ip_relay is much narrower: it forwards selected TCP streams through a user-space Perl process.
• The README also describes using it to simulate modem speeds while testing VNC over faster Ethernet links.

Sources

• https://formulae.brew.sh/formula/ip_relay
• https://stewart.com.au/ip_relay/
• https://stewart.com.au/ip_relay/CHANGELOG
• https://stewart.com.au/ip_relay/FAQ
• https://stewart.com.au/ip_relay/README