The Gym That Ran Out of Internet Addresses — and What It Taught Us About Consumer Routers in Commercial Spaces

We were called to a large gym that was experiencing a baffling problem. Every day, at some point in the afternoon — usually around peak hours — random pieces of equipment would lose their network connection. Treadmills couldn't sync. The sound system dropped out. The point-of-sale terminal became unreachable. Members' phones couldn't connect to the WiFi.

Two different IT people had been out before us. Neither could find the cause. The internet connection itself was fine. The WiFi signal was fine. Everything looked fine — until it didn't.

The problem turned out to be something most people have never heard of. And it was entirely caused by the wrong router for the job.

A quick explanation of IP addresses

Every device that connects to a network — a phone, a laptop, a treadmill, a smart TV, a camera — gets assigned an IP address. Think of it like a seat number: the network uses it to know where to send data. When your phone connects to WiFi, the router assigns it an IP address from a pool it manages.

The size of that pool — how many addresses the router can hand out — is set in the router's configuration. On a home router bought from a hardware store, that pool is typically set up to handle around 250 devices. That's fine for a house. It is not fine for a large gym.

What was happening at the gym

The gym had a home-grade router — the kind you'd buy for a typical household — managing the network. Nobody had noticed or thought to question it.

Connected to that network were: dozens of pieces of cardio equipment with built-in screens and internet connectivity, staff computers and tablets, point-of-sale systems, the sound and AV system, security cameras, smart lighting, and the personal phones of every member who connected to the guest WiFi when they arrived.

During quiet periods, the total device count was manageable. During peak afternoon hours — when the gym was full, equipment was running, and every member's phone had connected — the number of devices exceeded what the router could handle. It ran out of IP addresses to assign. New devices couldn't connect. Existing devices, when they briefly disconnected and tried to reconnect, couldn't get back on the network.

The problem resolved itself in the evenings when numbers dropped. Which is why it looked so mysterious — by the time anyone investigated, it had fixed itself.

Why the tradies couldn't find it

IP address exhaustion is a problem that only manifests at scale and under load. If you test the network when the gym is quiet, everything works perfectly. The router looks fine. The WiFi looks fine. The internet looks fine. The problem disappears.

Diagnosing it requires knowing to look at the router's DHCP pool — the list of IP addresses it's currently managing and how many are left. A network professional with the right tools finds this in minutes. Someone who came out to "check the WiFi" likely didn't look there at all.

The fix — and what should have been there from the start

The fix was replacing the home-grade router with a properly specified commercial router and configuring the IP address pool to handle several times the number of devices on the network. While we were there, we also set up proper network segmentation — member guest WiFi, equipment network, staff network, and POS network all separated from each other. The problem has not recurred.

The lesson is simple but important: a router designed for a home is not designed for a commercial environment. The device count, the concurrent connections, the security requirements, and the reliability standards are all different. Putting consumer hardware in a commercial setting is a false economy — it works until it doesn't, and when it doesn't, the cost in downtime and frustrated customers far exceeds the cost of doing it properly from the start.