Port 1936: HAProxy Stats — Where the Load Balancer Comes Clean

Port 1936 is officially unassigned. IANA hasn't given it to any protocol. But in practice, system administrators around the world know exactly what they'll find there: HAProxy telling you everything about itself.

What Actually Runs Here

HAProxy is one of the most widely deployed load balancers and proxies on the Internet. It routes traffic, balances load across servers, terminates SSL, and generally acts as the traffic cop in front of web applications.

Port 1936 is HAProxy's conventional home for its statistics interface — a real-time dashboard showing connections, request rates, server health, queue depths, and backend response times. You configure it in haproxy.cfg:

listen stats
    bind *:1936
    stats enable
    stats uri /haproxy?stats
    stats auth admin:yourpassword

Navigate to http://your-server:1936/haproxy?stats and you get a live view of everything HAProxy is doing: which backends are up, which are down, how many connections are queued, how fast requests are flowing.¹

Nobody told HAProxy to use 1936. It's a convention, not a standard.

The OpenShift Connection

The convention spread because Red Hat adopted it. OpenShift Container Platform — Red Hat's enterprise Kubernetes distribution — uses HAProxy as its default router, and it exposes the stats interface on port 1936 by default.²

That means across thousands of Kubernetes clusters running OpenShift, port 1936 serves HAProxy statistics and health checks. The /healthz endpoint on this port is what tells OpenShift whether its router is alive.³

An unofficial convention became de facto infrastructure.

This Port's Range

Port 1936 falls in the registered ports range (1024–49151). These ports are:

• Officially administered by IANA
• Intended for services that have registered with IANA
• Not reserved for any single service — many can share a port in practice

The registered range sits between the well-known ports (0–1023, which require root on most systems to bind) and the ephemeral ports (49152–65535, used for client-side connections). In this range, IANA can register services, but hasn't for 1936.⁴

What's Listening on Your Machine?

To check if anything is using port 1936:

# macOS / Linux
sudo lsof -i :1936

# Linux (alternative)
ss -tlnp | grep 1936

# Windows
netstat -ano | findstr :1936

If you see HAProxy there, everything is as expected. If you see something else, that's worth investigating.

Why Unassigned Ports Matter

The IANA registry exists so that two services don't collide — so a database and a web server don't accidentally reach for the same port number. But the registry only works if people register.

Port 1936 shows what happens when they don't: a convention forms anyway, spreads organically, and becomes effectively standardized through adoption. HAProxy chose 1936 for its stats, OpenShift shipped with 1936 as the router stats port, and now operators everywhere treat 1936 as "HAProxy territory" without any official backing.

It's not chaos. It's just informal consensus — the same way much of the Internet actually works.