虽然许多人认为互联网是“ WiFi ”，但它实际上只是您的设备和您正在使用的实际互联网连接之间的最后一座桥梁，无论是基于铜线的DSL、光纤、卫星还是烟雾信号。这意味着您的计算机和WiFi路由器之间的连接完全有可能在互联网连接本身断开时成功。
发生这种情况的原因可能不止几个，我们将介绍一些常见的故障排除技巧，以便在您的互联网已连接但无法正常工作时使用。
缩小罪魁祸首
您与整个互联网之间的链条中有很多链接。如果其中任何一个不能正常工作，那么你很可能会被切断网络。这使得找出问题的确切位置非常重要。这意味着您将知道要解决什么问题，或者问题是否在您的能力范围内。
尝试隔离系统的每个部分：
- 它是一个不起作用的特定网站吗？
- 您的网络上只有一台设备无法使用互联网吗？
- 路由器的指示灯是否显示连接到互联网？
通过回答此类问题，您可以减少大量浪费在与您遇到的问题无关的连接方面的故障排除工作。这也将帮助您决定可以跳过以下哪些（如果有）提示。
重新启动您的设备
如果您的互联网无法正常工作，这一解决方案既快捷又容易。无论您是使用电脑、平板电脑、智能手机还是智能电视。冰箱或连接互联网的墨西哥卷饼，请尝试重新启动设备。有时会出现我们无法手动查找或解决的临时故障。一个新的开始可以帮助消除这些。
如果您发现设备的互联网连接问题经常需要通过重启来解决，您可能需要查看操作系统或固件更新，因为这可能是系统性问题。
您(Are)连接到正确的路由器(Right Router)了吗？
没有愚蠢的问题，即使这看起来像是一个问题。只需(Just)仔细检查您是否已连接到您认为的WiFi连接。(WiFi)例如，您可能不小心连接到忘记关闭的移动热点。
另一个常见问题发生在双频路由器上，它以两个不同的名称提供2.4Ghz 和 5Ghz WiFi 网络。(2.4Ghz and 5Ghz WiFi network)5Ghz WiFi不适合长距离传输，尤其是穿墙。如果您的设备在信号过低时无法切换到 2.4Ghz 网络，则您的互联网连接将无法正常工作。所以手动切换到 2.4Ghz 网络来解决这个问题。
你有良好的信号强度吗？
继上一点之后，无论网络频率如何，您是否都有足够的信号强度？如果当您靠近路由器时您的互联网连接重新开始工作，请考虑使用某种WiFi 扩展器或中继器(WiFi extender or repeater)。
检查、重置或重启您的路由器
如果互联网连接问题影响连接到路由器的所有设备，您一定要注意路由器本身。在做任何激烈的事情之前，请检查其WAN灯是否亮起。如果没有，路由器没有连接到互联网，你的ISP可能有问题。
首先简单地拔掉它，等待一分钟，然后重新插入。路由器实际上只是专门的计算机，它们可以像 PC 一样挂起、崩溃和行为不端。
如果一切都失败了，您可能还需要尝试硬重置路由器。请参阅其手册以了解如何执行此操作。它通常是一个嵌入式按钮，您必须按住几秒钟。但是，您将不得不重新输入您的ISP、WiFi网络密码等的所有设置。被警告！
在 WiFi 和以太网之间切换
如果WiFi无法正常工作，但直接以太网(Ethernet)电缆连接正常，则表明这是与WiFi相关的问题。如果所有设备都在WiFi上遇到困难，请查找一般WiFi问题，然后参考上述重置路由器的内容。
如果它只是一个无法通过WiFi工作的特定设备（但可以与以太网(Ethernet)一起工作），您将不得不专门对其WiFi进行故障排除。
DNS 缓存问题
如果 Internet 无法正常工作，一种快速解决方法是刷新您的DNS缓存。每次您输入网站地址时，您的计算机都会向域名服务器(Domain Name Server)发送请求，将其转换为特定服务器的 IP（互联网协议）地址。
您计算机的DNS缓存会存储您之前访问过的网站的信息，以加快您的互联网体验。问题是，如果缓存出现问题，您可能无法访问该站点。
要刷新缓存：
- 打开开始菜单
- 键入CMD并运行命令提示符应用程序
- 键入ipconfig /flushdns并按 Enter
就是这样，您的DNS缓存现在已清空，如果这是问题所在，一切都应该再次正常工作。
使用备用 DNS 服务器
有时，互联网访问问题是由DNS服务器本身不可靠或停机引起的。大多数互联网服务提供商都运行自己的DNS服务器，默认情况下会通过路由器对其进行配置。
您可以更改特定设备或路由器使用的DNS服务器，以便始终使用更快或更可靠的选择。有关如何在Windows中更改(Windows)DNS服务器的详细信息，请参阅如何在 Windows 中更改 DNS 提供程序(How To Change Your DNS Provider In Windows)。
IP 地址冲突
假设您的路由器和设备设置为使用动态 IP 分配，您本地网络上的每台设备都有一个由路由器分配给它的唯一 IP 地址。这是默认设置，但在某些情况下，设备或路由器本身已设置为使用静态 IP 地址。
使用静态 IP 地址的原因有很多，但如果网络上的两台设备碰巧配置为使用相同的地址，则两者都无法使用网络。
解决IP地址冲突确实需要一篇单独的文章，你不知道吗，我们恰好有这样一篇文章。因此，如果您认为网络上可能存在 IP 地址冲突，请查看如何修复 IP 地址冲突(How to Fix an IP Address Conflict)。
检查您的ISP是否(ISP)有停机时间或(Downtime Or)远程重置您的连接(Connection)
您已达到最后一个故障排除提示，但您的互联网仍然无法正常工作。它不是特定的设备，也不是您的路由器，您的本地域中似乎没有任何问题。好吧(Well)，那只剩下您实际的互联网服务提供商了。
好消息是，许多ISP(ISPs)会在其网站上发布有关停机的通知，您可以使用手机或其他人的互联网查看。您也可以简单地给他们打电话，询问他们是否存在已知问题。
即使没有，有时您也可以通过从ISP方面请求网络重置来解决问题。这可以通过他们网站上的自助服务来完成，或者您必须使用支持票来请求它。如果这仍然不起作用，请让他们在线获得一些急需的技术支持！
10 Troubleshooting Tips If Your Internet Is Connected But Not Working
While manу people think of the internet as “WiFi” it’s actually just a final bridge between your device and the actual internet connection you’re using, whether that’s copper-based DSL, fiber, satellite or smoke signals. This means it’s entirely possible for the connection between your computer and the WiFi router to be successful while the internet connection itself is down.
There can be more than a few reasons why this happens and we’re going to run through some common troubleshooting tips to use if your internet is connected but not working.
Narrow Down The Culprit
There are a lot of links in the chain between you and the internet at large. If any one of them aren’t working properly then you’re likely to be cut off from the net. Which makes it pretty important to work out where exactly the issue is. That means you’ll know what to fix or whether the problem is within your power to solve at all.
Try to isolate each section of the system:
- Is it one specific website that doesn’t work?
- Is it only one device on your network that can’t use the internet?
- Does the router’s indicator light show a connection to the internet?
By answering questions like these, you can cut out a lot of troubleshooting work wasted on aspects of the connection that have nothing to do with the problems you’re experiencing. This will also help you decide which (if any) of the tips below you can skip.
Restart Your Device
This one solution if your internet is not working is quick and easy to do. Whether you’re on a computer, tablet, smartphone, smart TV. fridge or internet-connected burrito, try restarting the device. Sometimes temporary glitches develop that we can’t find or resolve manually. A fresh start can help eliminate those.
If you find your device’s internet connection issues frequently need to be resolved with a restart, you may want to look into operating system or firmware updates, since it could be a systematic issue.
Are You Connected To The Right Router?
There are no such things as dumb questions, even though this might seem like one. Just double check that you’re connected to the WiFi connection you think you are. For example, you may have accidentally connected to a mobile hotspot you forgot to turn off.
Another common issue happens with dual-band routers, which offer a 2.4Ghz and 5Ghz WiFi network under two separate names. 5Ghz WiFi isn’t great at long distance transmission, especially through walls. If your device fails to switch over to the 2.4Ghz network when the signal drops too low, you won’t have a working internet connection. So change to the 2.4Ghz network manually to resolve this.
Do You Have Good Signal Strength?
Following from the previous point, do you have enough signal strength regardless of the network frequency? If your internet connection starts working again when you move close to the router, consider using a WiFi extender or repeater of some sort.
Check, Reset Or Restart Your Router
If the internet connection issue affects all of the devices connected to the router, you should definitely pay some attention to the router itself. Before doing anything drastic, check if its WAN light is lit. If not, the router has no connection to the internet and your ISP is probably at fault.
Start by simply unplugging it, waiting a minute and then plugging it in again. Routers are really just specialized computers and they can hang, crash and misbehave just the same as PCs.
You might also need to try a hard reset of your router if all else fails. Refer to its manual on how to do this. It’s usually a recessed button you have to hold in for a few seconds. You will have to re-enter all the settings for your ISP, WiFi network password and the like however. Be warned!
Switch Between WiFi & Ethernet
If WiFi isn’t working properly, but a direct Ethernet cable connection does, that’s a sign it’s a WiFi related issue. If all devices struggle over WiFi, look for general WiFi problems and refer back to the above on resetting your router.
If it’s only one specific device that won’t work over WiFi (but works with Ethernet) you’ll have to troubleshoot its WiFi specifically.
DNS Cache Problems
One quick fix if the internet is not working is to flush your DNS cache. Every time you type in the address of a website, your computer sends a request to a Domain Name Server to have it translated into the IP (internet protocol) address of a specific server.
Your computer’s DNS cache stores the information of sites you’ve visited before to speed up your internet experience. The problem is that if something goes wrong with the cache, you might lose access to the site.
To flush the cache:
- Open the Start Menu
- Type CMD and run the Command Prompt app
- Type ipconfig /flushdns and hit Enter
That’s it, your DNS cache is now emptied and if that was the problem everything should work again.
Use Alternative DNS Servers
Sometimes internet access issues are caused by the DNS servers themselves being unreliable or down. Most internet service providers run their own DNS servers and will configure them through the router by default.
You can change which DNS servers your specific device or router uses so that you always use a faster or more reliable choice. For more information on how to change DNS servers in Windows, please refer to How To Change Your DNS Provider In Windows.
IP Address Conflicts
Every device on your local network has a unique IP address assigned to it by your router, assuming that your router and devices are set up to use dynamic IP assignment. This is the default, but in some circumstances a device or the router itself has been set up to use static IP addresses.
There are plenty of reasons to use static IP addresses, but if two devices on the network happen to be configured to use the same address, neither can use the network.
Resolving IP address conflicts really needs an article all to itself and, wouldn’t you know it, we happen to have just such an article. So if you think there might be an IP address conflict on your network, check out How to Fix an IP Address Conflict.
Check Your ISP For Downtime Or Reset Your Connection Remotely
You’ve reached the last troubleshooting tip and your internet is still not working. It’s not a specific device, it’s not your router, nothing in your local domain seems to be to blame. Well, that only leaves your actual internet service provider.
The good news is that many ISPs will put notices about downtime on their websites, which you can check using a mobile phone or someone else’s internet. You can also simply phone them and ask if there’s a known issue at their end.
Even if there isn’t one, sometimes you can fix issues by requesting a network reset from the ISP side of things. This may be possible to do through self-service on their site or you’ll have to request it using a support ticket. If that still doesn’t work, keep them on the line for some much-needed technical support!
