Of all the types of problems you can have with your computer, network issues might be one of the worst. Though our computers can do a lot offline, being cut off from the internet isn’t fun. Even worse, when you can’t get online, you can’t easily research fixes for your problem.
Let’s step through the process you should perform to diagnose network issues. That way, next time you open up your web browser to a “Cannot Connect” message, you’ll know what to do. Like all troubleshooting, we’ll start broadly and narrow down to specifics.
After each step, attempt to connect to a web site to verify your connection is working. If it still doesn’t work, continue to the next part.
0. Make Sure It’s Your Problem
Sometimes what seems like a network outage is actually a problem on a specific website’s end. If you can’t get on Twitter, check another few websites to make sure that it’s not just them. You can use IsUp.me to check if a website is down for everyone or just you.
1. Power Cycle Everything and Check Other Devices
There’s no need to get upset right away, as the fix to your problem might be as simple as rebooting your equipment. Restarting fixes a ton of issues, so make sure it’s your first response to network issues, too.
Go ahead and reboot your PC, as well as your modem and router. To clear the modem and router caches, wait 60 seconds before you turn them back on again. Turning everything off and back on first ensures that it isn’t a temporary problem. It’s better to reboot now than to waste 30 minutes continuing on when you don’t need to.
After a little "power cycle" issue our internet and phone connections are working again. Pretty easy
— UnNam3d #EggNogBoy (@unnam3d97) October 29, 2016
Once you’ve restarted, if you have another computer (or a mobile device), try to get online with that machine. If you find that no devices can connect, it’s likely an issue with your equipment or your ISP.
Should you find that only one computer can’t get online, you can continue to narrow down the problem. On that device, make sure to run an antivirus scan to ensure you don’t have malware interfering with your connection. Make sure that your firewall settings weren’t changed.
Finally, try using a different browser to see if your usual one is damaged.
2. Check Physical Connections
Does your problem persist after rebooting? Before we start diving into settings and tests, the next thing to check is that you’re physically connected. If you use an Ethernet cable to connect to your router, check to make sure that it’s not unplugged. If your laptop has a physical wireless switch (check specific tips for fixing wireless connections), make sure that it didn’t get bumped to the off position.
Once you’ve verified a proper connection, check your equipment. Are the lights on your router and/or modem flashing green as normal? If no lights come on after the reboot, the device could be dead. If you get red lights, or a power light but no connection light, your ISP is likely down.
3. Run the Network Troubleshooter
Windows includes some built-in troubleshooters that can automatically find and fix issues. To run the troubleshooter for network problems, right-click the network icon in your System Tray and choose Troubleshoot Problems. Once the troubleshooter runs, it could fix issues, find issues but fail to fix them, or find no issues.
If the troubleshooter finds a problem that it fixes, try to connect again. If you get a specific error or problem name that Windows can’t fix automatically, take note of it for later research.
So has the Windows network troubleshooter ever actually worked for anyone? Ever?
"Click here to see if we can fix your problem .
— Jeff Powers (@bubbicus) October 4, 2016
4. Check for a Valid IP Address
At this point, we’ve verified that the problem is not temporary and that all of our hardware works. Since Windows can’t fix the problem on its own, we need to pinpoint the spot along the connection where the problem is occurring.
It’s a good idea to make sure that you don’t have any strange IP settings selected. To check this, type Network and Sharing Center into the Start Menu to open that utility. On the right side, where you see Connections, click the name of your Wi-Fi or wired network. Choose Properties and double-click internet Protocol Version 4.
Unless you’ve set up a static IP (if you don’t know what this is, you probably don’t use one), make sure to check Obtain an IP address automatically and Obtain DNS server address automatically. Repeat this process for internet Protocol Version 6 to ensure that everything is automatic there, as well.
Once you’ve done this, we can check to confirm the router is giving you a valid IP address. Open up a command prompt by typing cmd into the Start Menu. Type ipconfig and look for the text under Ethernet adapter (for wired connections) or Wireless LAN Adapter (for wireless connections).
If IPv4 Address starts with 169.x.x.x, your computer is not receiving a valid IP address from your router. Typing the following two commands may resolve this:
ipconfig /release ipconfig /renew
Should you still have a 169.x.x.x address after typing the above commands and ipconfig again, your machine still isn’t receiving an IP from the router. Try plugging your PC directly into the modem with an Ethernet cable and see if you can get online. If so, your router is the problem.
5. Try a Ping and Trace Its Route
If your IP address starts with anything other than 169 when you run ipconfig, you have a valid IP address from your router and the problem is occurring between your router and the internet.
Type this command to ping Google’s DNS servers to see if you can get online: (you can replace 220.127.116.11 with anything, such as www.msn.com)
This will send four packets to Google. If they fail to send, you’ll be told what the problem was. For more information, type this line to trace the route between your computer and Google’s DNS servers:
The above command gives you a step-by-step breakdown of the path that the information takes to reach the destination you specify. Watch it, and if it fails, check to see where the problem occurs. If an error pops up early in the route, the issue is likely with your local network.
6. Contact Your ISP
Should all the above steps complete successfully, we’ve verified that our equipment is working, we have a valid IP address from the router, and the problem is occurring outside of our network for multiple devices. If this is the case, your next best option is to find out if your ISP is having issues.
Using your smartphone will prove useful here, as you can look up an outage map (like DownDetector.com) for your provider or check Twitter to see if others in your area are experiencing issues as well. If you don’t see anything of note online, try giving your ISP a call to see if there are known issues. Perhaps line issues are affecting a small area; they will be able to run tests to check.
7. Wait It Out
Once you’ve let your ISP know of the issue and confirmed that it’s not just one computer having a problem, all you can do is wait. Many times, you can’t fix network issues on your own. When attackers took down half the internet in late October, none of the above steps helped users get back online. If your ISP is aware of the issues, hopefully they’ll get everything fixed in a short time.
While you’re waiting, there are plenty of things to do when you can’t get online.
These steps are a general template for diagnosing network issues, as your exact setup may differ. In general, respond by restarting everything, seeing if multiple devices are having trouble getting online, and checking to make sure your settings are correct, per the above. If you’ve checked all of this, the issue is probably with your ISP.
Fixed your network problem, but still have a slow wireless connection? Find out how to fix slow Wi-Fi.
What steps do you take when you can’t get online? Let us know if these tips helped you by leaving a comment!
Originally written by Karl L. Gechlik on January 16, 2010.
Image Credits:connectivity by Andreas Beer via Flickr