When Your WiFi Extender Hijacks The Network: The Rogue Router Problem

With over 20 years in IT, I’ve seen the good, the bad, and the outright ugly of network setups. My own home network isn’t your average plug-and-play setup. It’s a carefully built system, running from a cable modem through an Opnsense firewall down to enterprise-grade switches, access points, and even VOIP phones. Every device is tuned to work in harmony, all without a single call for support.

Why mention this? Because in my line of work, I’ve helped troubleshoot countless networks gone wrong, often due to well-meaning users adding devices like WiFi extenders without understanding how they can disrupt everything. Let’s take a closer look at what happens when a rogue device throws your network into chaos—and what you can do to avoid it.

What Is a WiFi Extender, Really?

A WiFi extender might seem like a simple device—it promises to boost the WiFi signal to those hard-to-reach corners of your home. But in reality, an extender does more than just “repeat” your existing signal. When set up correctly, an extender acts as an assistant, expanding your network’s reach by rebroadcasting the WiFi signal without interfering with your main router’s role.

However, many extenders also have a “router mode,” which isn’t always obvious to users. In router mode, an extender stops being a simple assistant and starts acting like a second router, trying to manage your network traffic independently. When that happens, rather than boosting your WiFi, the extender can create a second network that clashes with your main one—causing slow speeds, dropped connections, and endless frustration. Understanding this distinction is key to getting the most out of your extender without accidentally creating network chaos.

Routed vs. Bridged Mode: The Key to a Stable Network

When setting up a WiFi extender, one of the most important settings you’ll encounter is whether it operates in routed mode or bridged mode. These two options sound technical, but the difference between them can make or break your network’s stability. Here’s a closer look at each mode and why choosing the right one matters.

In routed mode, the extender is configured to act as a full-fledged router. This means it’s not just passing along the signal from your main router; it’s creating its own network, complete with its own IP addresses and, in some cases, its own network name (SSID). While this sounds helpful, routed mode comes with serious downsides in a typical home network. When the extender starts assigning IP addresses or managing network traffic, it begins to conflict with your main router. Devices can end up on different networks, creating “double NAT” issues (when two devices are translating addresses independently). This setup results in slowed speeds, connection drops, and generally unpredictable behavior across the network.

On the other hand, bridged mode is designed to avoid these conflicts by making the extender a passive participant. In bridged mode, the extender connects directly to your main router and simply relays the existing WiFi signal without trying to manage the network itself. The extender doesn’t create its own IP addresses or interfere with network traffic—it’s purely a range extender, which is what most users actually want. Devices stay on the same network, receiving their IP addresses from the main router, keeping things simple and seamless.

In most home setups, bridged mode is the way to go for WiFi extenders. It keeps the network unified, with only one device acting as the “brains” behind your network. Routed mode might be useful in specialized setups where a separate network is required, but for extending WiFi coverage, bridged mode will deliver a smoother, more reliable experience. Understanding this difference is crucial, especially when you’re looking to avoid connectivity issues and keep your network running smoothly.

Symptoms of a Rogue Router

When a WiFi extender—or any secondary device—tries to act as a router on your network without proper configuration, it can create what I like to call a “rogue router” situation. This rogue device quietly competes with your main router, and the effects can range from subtle to downright maddening. Here are the telltale signs that a rogue router may be at work in your network.

1. Inconsistent Connectivity: One of the most common symptoms is devices dropping connections or struggling to connect reliably. You may notice that some devices lose WiFi unexpectedly or reconnect to the network on their own. This is often due to conflicting instructions from both routers, causing devices to “jump” between networks.
2. Slow Speeds and Buffering: When there’s a rogue router on the network, speeds tend to suffer. Double NAT issues (where two routers handle address translation) can create a bottleneck, which means streaming videos, online gaming, and even basic browsing may feel slower than usual, or you may see buffering where you never did before.
3. VPN and Gaming Issues: Some applications, like VPNs and online games, are especially sensitive to double NAT and network conflicts. You might experience increased latency (lag), frequent disconnects, or be unable to connect at all. In these cases, having multiple routers on the same network can disrupt the reliable connectivity that these applications need.
4. Strange IP Addresses and Gateways: If some of your devices show unusual IP addresses or gateways that don’t match your main router’s IP range, this is a big clue that there’s another device acting as a router. Devices may end up with addresses from two different pools, and when that happens, the network becomes split, creating partial or unreliable connectivity.
5. Firmware Update Failures: Even your main router can be affected by a rogue device. When routers try to check for firmware updates, they rely on a stable connection to their update servers. A rogue router can interfere with this process, leading to failed or incomplete updates, which can leave your network open to security vulnerabilities.
6. Smart Home Devices Going Offline: Smart devices like thermostats, lights, and speakers are often the first to “feel” the effects of network inconsistency. Many IoT devices don’t handle switching between networks well, and if they’re bouncing between the main router and a rogue extender, they can drop off the network altogether.

These symptoms might appear sporadically or all at once, but if you’re noticing even one or two of them, there’s a good chance that a rogue router could be the culprit. Recognizing these signs early is key, as this problem usually doesn’t solve itself—in fact, it tends to get worse over time as devices compete for network control.

How to Check for a Rogue Router

If you’re noticing issues like dropped connections or slow speeds, there’s a chance a rogue router could be causing trouble on your network. Tracking down this rogue device can be a little tricky, as every network setup is different. However, if you’re using a Calix Gigaspire router, the steps below will help you determine if there’s a conflicting router on your network.

In most setups, the main router has a specific IP address that all devices should use as their “default gateway.” For example, in our Calix Gigaspire setup, the router’s IP is 192.168.1.1, but this address can vary by ISP or router model. If you’re unsure of your router’s IP address, check the label on the bottom of the device, which often lists it. Otherwise, your ISP should be able to confirm it.

Here’s how you can check if your devices are following the correct default gateway or connecting to a rogue router.

1. Identify the Default Gateway on Each Device:
   • The “default gateway” is the IP address that each device uses to connect to the internet through your main router. To check it:
     • Windows: Open Command Prompt, type ipconfig, and look for “Default Gateway.”
     • macOS: Open Terminal, type netstat -rn | grep default.
     • iOS/Android: Go to WiFi settings, select your network, and check the “Router” or “Gateway” IP.
   • Compare the default gateway IP on each device. All devices should ideally have the same gateway (e.g., 192.168.1.1 for a Gigaspire setup). If you see a different IP address, that device may be following a rogue router.

If you spot a rogue gateway on one of your devices, there’s a simple trick to identify it. Even if that rogue router isn’t connected to the internet, you can often still access its admin page. Just open a web browser on the device with the suspicious gateway, type the gateway’s IP address into the address bar, and press Enter. This should load the login page for the rogue router, giving you a chance to see what device is trying to control part of your network.

This method works nearly every time and can be a quick way to identify the intruder, see its model or brand, and confirm if it’s in router mode. Once identified, you can then take steps to reconfigure it or remove it from your network.

By identifying these signs, you’ll be able to tell if there’s a rogue router lurking on your network. If you do find one, the next step is to reconfigure it (usually by switching it to bridge mode) to prevent it from taking over your network’s routing duties. Remember, the IP and exact steps may differ based on your ISP and router model, so consult your device’s manual or ISP if anything looks different from these instructions.

Why Rebooting the Main Router Helps: For a Bit

When you’re dealing with a rogue router on your network, one of the most common fixes—rebooting the main router—can offer temporary relief. After a reboot, it often seems like everything’s back to normal. Devices reconnect, speeds pick up, and connections appear stable. But after a while, the same issues creep back in. Why? Because while rebooting resets the network temporarily, it doesn’t address the underlying problem of conflicting routers.

Here’s what’s really happening. When you reboot the main router, all connected devices are forced to reconnect. In many cases, they’ll initially connect to the main router at its correct IP (say, 192.168.1.1 on a typical setup). For a brief period, your devices follow the main router’s lead, and everything appears stable. But as soon as the rogue router starts broadcasting its own instructions, things begin to unravel again. The rogue device slowly starts pulling some of those devices back under its control, sending out conflicting information that corrupts the main router’s routing table.

Once the rogue router resumes its push, devices get confused. They may switch over to the rogue’s IP address, or they may try to follow both routers, resulting in erratic behavior. Speeds slow down, connections drop, and that seamless experience you had right after rebooting disappears. Without addressing the rogue router directly, this cycle will keep happening, leaving you rebooting your main router every time the network acts up.

So while rebooting can give you a temporary fix, it’s a bit like resetting the clock on a ticking time bomb. To truly fix the issue, you need to locate and reconfigure the rogue router—only then will your main router be able to do its job without interruption.

Case Study: The $4,000 WiFi Extender Chaos

A while back, I got a call to troubleshoot a 15,000-square-foot home with a WiFi setup that, on paper, should have been bulletproof. The owner had shelled out $4,000 to a big box store for a professional installation of Amazon Eero extenders, expecting flawless WiFi coverage throughout the estate. But instead of seamless internet, they were plagued with dropped connections, devices refusing to connect, and speeds that seemed slower than ever.

Upon investigation, it was clear that the high price tag and professional setup hadn’t delivered the network stability they’d been promised. Here’s what was really going on: the main Eero unit had been set up in router mode, hijacking the entire network. The ISP-provided router was supposed to manage everything at 192.168.1.1, but instead, the Eero had set itself up at 192.168.1.150. This rogue gateway was commandeering devices to follow its lead, effectively taking over the network right under the ISP router’s nose.

Here’s how this played out on the ground:

• Rogue Gateway Conflict: With the Eero asserting itself at 192.168.1.150, it was creating a confusing hierarchy. Some devices remained loyal to the ISP’s router at 192.168.1.1, while others—randomly scattered across the house—were redirected to follow the Eero’s rogue gateway. This created a split-brain scenario where devices didn’t know which router to trust, leading to random disconnections and constant “network unavailable” errors.
• Double NAT Disaster: With both the Eero and the ISP router attempting to manage NAT independently, a double NAT issue cropped up across the network. Each router was translating network addresses, causing bottlenecks that dragged down speeds and prevented stable connections. Video streaming, online gaming, and even basic browsing were affected. Devices bounced between these two routers, each trying to lead them in a different direction.
• Smart Devices Out of Sync: Smart home devices were the first to buckle under the split-network load. IoT gadgets like thermostats, smart speakers, and security cameras aren’t built to handle multiple conflicting gateways. They repeatedly dropped off the network, failed to reconnect, or appeared offline altogether. The homeowner couldn’t rely on their smart home devices because they were left guessing which router to follow.

The fix wasn’t complicated, but it required a key reconfiguration: I logged into the Eero’s settings and switched it from router mode to bridge mode. This change allowed the Eero system to act purely as a range extender, leaving the ISP router in charge. Once the Eero stopped acting as a competing gateway, the network stabilized. The five additional Eero units automatically followed suit, serving as seamless extenders instead of rogue participants.

With this one change, devices across the home began connecting consistently, the double NAT vanished, and speeds finally matched the homeowner’s expectations. The network was no longer a battlefield between two competing routers; it was one unified system.

The takeaway? Even a high-end installation can go wrong without the right settings. When configuring a network, it’s essential to understand how routers, extenders, and bridge mode work together. Without that understanding, you might end up paying thousands for a rogue network that does more harm than good.

Support Is Here to Help You

If you’re experiencing network issues and call in for support, there’s a good chance we’ve seen your problem before—especially if it involves WiFi extenders or other add-on devices. We’ve been dealing with situations like this more often, where a rogue extender or secondary router has unknowingly thrown off the balance of the network. So, if we tell you that a device you installed might be causing trouble, it’s not about pointing fingers. We’re just as committed as you are to getting your network running smoothly—because, believe me, we want it rock-solid too.

The truth is, I tend to put the blame on manufacturers who often leave users in the dark with confusing or overly technical setup instructions. Those manuals are written by engineers who know the details but don’t always understand the frustrations of a typical home user. This often leads to extenders being installed in router mode or other configurations that create chaos on your network, even though the intent was to improve it.

When we tell you that a device may be causing the problem, it’s not a judgment on your setup skills. We know you added it with the best intentions, and we get that it’s frustrating to hear it might be creating problems. But the fact is, we’re just as motivated to get this fixed as you are—when your network is rock-solid, we don’t have to keep having these conversations! Our goal is a stable, reliable connection for you, one that works so well you don’t even think about it.

So, if you’re dealing with these kinds of issues, don’t hesitate to reach out. We’re here to help troubleshoot and guide you through any adjustments needed to restore stability. A few small changes can make all the difference, and once your network’s up and running smoothly, you can enjoy it—and we can focus on helping someone else!

Bringing It All Together

At the end of the day, a stable network isn’t just about having the right hardware—it’s about understanding how all those pieces work together. WiFi extenders, routers, and access points are powerful tools, but without the right setup, they can turn from helpful solutions to network troublemakers in no time. Whether you’re expanding your WiFi coverage or setting up smart home devices, a few simple principles, like choosing bridge mode over router mode for extenders, can help avoid most of these common pitfalls.

When something goes wrong, know that we’re here to help. We’ve seen it all and understand that these issues can be frustrating, especially when you’ve invested in devices meant to improve connectivity. Manufacturers don’t always make it easy, and we get that. Our goal is to help you troubleshoot and get your network running smoothly, without any of the tech jargon or frustration.

A strong, reliable network should be effortless, letting you connect with confidence, whether you’re working, streaming, or managing your smart home. With a bit of guidance and some minor adjustments, you can have a network that runs as seamlessly as you expected from the start. And when it does, you’ll likely find yourself calling us a whole lot less. That’s our goal, and we’re here to help you get there.

--The Truth is Out There
-Bryan