Last Updated on October 15, 2021 by Dave Farquhar
How do you reboot a modem and router? And does it really do any good? The occasional reboot can be good preventative maintenance, so here’s how to do it, why, and how frequently. And while rebooting is something tech support tends to use as a crutch, it’s also frequently very effective. That’s why it’s always been one of the first things I try when troubleshooting.
There are usually two or even three ways to reboot your router, and there may be more than one way to reboot your modem. Usually the simplest, safest way is just to power-cycle them.
Which is the modem and which is the router?
The first question to answer is which device is your modem and which is your router. And in some cases, the two devices may be integrated into a single unit. AT&T generally does it this way now.
The modem is the device that establishes your Internet connection. It can talk with one device at a time. Generally speaking, they tend to be boxier and more industrial looking.
Your router is a multi-function device that does several things, including provide your wireless connection. But the most critical thing it does is let more than one device use the Internet connection. It’s much more complicated than just a line splitter, but you can think of it kind of like one. Since routers are consumer devices, router makers are more likely to pay attention to industrial design. The router may or may not look nicer than the modem, but its design will probably be less boxy and more imaginative.
Your modem will have one line coming into it from the wall, and one modular RJ-45 jack for connecting to another device. A router will have several RJ-45 jacks for plugging in multiple computers. If you just have one box that seems to have both characteristics, you have a combo device that integrates both functions.
How to reboot a router
Usually there are at least three ways to reboot a router. You can log into the router and use an option in its web GUI. The problem with this method is there is no standard place for the option, and it also requires multiple steps. It’s the most proper way to do it, but it’s by far the most inconvenient. Most people don’t bother with this method.
Many routers also have a reset button, usually on the back near the power cord. The button often is recessed so you don’t accidentally bump it, so you may have to use the tip of a ballpoint pen to reach it. The problem with reset buttons is that holding them a long time will usually erase the device’s memory, so you may want to avoid using it.
By far the easiest and most convenient way to reboot a router is to simply turn off the power and turn it back on. I recommend that you want about 30 seconds before turning the power back on. The reason for this is some of the components inside the router don’t discharge immediately. Part of the reason to reboot is to clear the router’s memory, and if you cycle the power too quickly, you won’t clear the memory completely. A well-behaved router will clear its memory as part of its startup process, but not all routers seem to be well designed.
And if you can’t find the power switch for some reason, or the device doesn’t have one, just pulling the plug is an acceptable alternative. Whatever works, right?
How to reboot a modem
Modems are usually black boxes with no user interface, because there’s rarely anything to configure in them, at least from the end user standpoint. Usually the two ways to reboot a modem are to use a reset button, which is usually on the back of the unit and recessed, or cycle the power.
A reset button on a modem is less likely to cause problems, but it’s also less likely to solve the problem since it doesn’t actually discharge any electrical components.
With a modem, I definitely recommend cycling the power, and I also recommend waiting the full 30 seconds before switching the power back on. Depending on the design of the modem, that 30-second wait time can be more critical on a modem than a router.
How to reboot a combination device
If you have a combination modem/router device, it probably has two or three different methods, just like a router. I recommend shutting off the power, waiting 30 seconds, then powering a combination device back on.
I recommend avoiding the reset button on combination devices for the same reason as on modems. Holding the reset button for 30 seconds often erases the device’s configuration, requiring you to set it up again from scratch. Usually that’s overkill.
What order to reboot the modem and router in
If you don’t have a combination device, the order you reboot the devices in is critical. The router won’t function if the modem isn’t up and running yet. Your computers and other devices can talk to the router, but the router is just talking to the wall because the modem isn’t capable of listening yet.
If both devices are malfunctioning, or you don’t know which of the two devices are malfunctioning, reboot the modem first. When all the lights show a good status with no faults, reboot the router. The router usually takes less time to come back.
The safest bet is to power cycle the modem, wait for it to come back, then power cycle the router. Once you know about how long it takes for the modem to come back, you can cheat. If the modem takes two minutes to come back and the router takes one minute, you can reboot the router when the modem has about a minute left. The key is for the modem to be ready when the router comes back. If the router is waiting on the modem, your other devices may think they have an Internet connection when they don’t yet.
Some people will tell you to wait 60 seconds in between the two devices. That’s not bad advice, but it’s not universal. Unless something is wrong with your line, a minute usually gives your modem enough time to lock on before your router finishes coming back online, but your modem could be a bit faster. If all the lights are good, there’s no reason to wait that full minute between devices.
How to know which device is causing trouble
When you’re having a problem, the easiest thing to try is just restarting both the modem and router. But if you don’t have a combo device, you can often save time by just rebooting the one that’s having trouble. The key is knowing what normal looks like. On my devices, green lights usually mean everything is working properly. Some of the lights, like the status light, are solid. Activity lights normally blink.
A status light that’s blinking or out usually indicates something is wrong. It’s also common for a light to be yellow or red when something isn’t functioning, and green when it is.
If one device is showing red or yellow lights and the other is all green, by all means try rebooting just that device first, and see if the other one recovers. More often than not, that shortcut will work just fine.
How often to reboot your modem and router
Knowing tech support people, they’ll tell you to reboot your modem and router every 30 days. But there’s nothing especially significant about 30 days. The operating systems that routers run are capable of running uninterrupted for years at a time. The question is how reliable the software is running on top of that operating system. Thirty days is a safe guess because that’s how long your desktop computer runs in between reboots, most of the time.
I recommend rebooting your router more frequently than that. Once a week or even once a day is better, if you can schedule it. But that’s for security reasons, not for reliability reasons. If your router is malfunctioning on a weekly basis, it’s probably time for a new one.
With modems, there’s no hard and fast rule. Modems can also run for years uninterrupted. Usually they don’t need to be rebooted unless something happens upstream and the modem gets hopelessly confused. When I had a separate modem (I don’t at present), I just rebooted it when I had problems.
If your modem frequently has problems locking onto a signal, contact your Internet provider and ask for a line test. The problem could be the modem, but it could just as easily be the line. You can’t test both, but your Internet provider can. Also, if your neighbors have the same provider and they also frequently have Internet problems, it’s not likely all your modems went bad at once. It’s more likely to be line problems in that case.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.