en:troubleshooting:debugging_your_internet_connection
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en:troubleshooting:debugging_your_internet_connection [2022-08-05-15-42] – [Am I Listening to Myself? IP Stack Damaged] 7saturn | en:troubleshooting:debugging_your_internet_connection [2022-08-07-21-17] – sw | ||
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If you cannot reach the Google DNS server, your internet connection may indeed be down. But that must not be the case. (Yes, Google may also be down, but that is very unlikely. So we just assume it is not down.) Head on to the next step. | If you cannot reach the Google DNS server, your internet connection may indeed be down. But that must not be the case. (Yes, Google may also be down, but that is very unlikely. So we just assume it is not down.) Head on to the next step. | ||
==== In Which Direction Is the Internet, Please? The Standard Gateway ==== | ==== In Which Direction Is the Internet, Please? The Standard Gateway ==== | ||
- | You could not reach the Google DNS via its IP address but others don't seem to have you initial problem. The next step is finding out, whether the Internet connection is down, or something else along the way to the internet. If you for example cannot reach your own router (which routs the internet traffic to your computer and vice versa), you of course cannot reach the internet either. In order to find out, what's going wrong, enter this into the cmd: | + | You could not reach the Google DNS via its IP address but others don't seem to have your initial problem. The next step is finding out, whether the Internet connection is down, or something else along the way to the internet. If you for example cannot reach your own router (which routs the internet traffic to your computer and vice versa), you of course cannot reach the internet either. In order to find out, what's going wrong, enter this into the cmd: |
'' | '' | ||
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If the gateway does //not// respond or is not set (even after checking all hardware is plugged in and you have a wireless connection), | If the gateway does //not// respond or is not set (even after checking all hardware is plugged in and you have a wireless connection), | ||
==== My Little Island (Wrong IP Configuration) ==== | ==== My Little Island (Wrong IP Configuration) ==== | ||
- | You do have an IP address, but it leads nowhere. This is usually the case, when someone™ messed with the IP configuration locally. Check whether your IP configuration is set to automatically receiving an IP address (in opposition to setting it manually). You can see this by opening your settings and select //Network & Internet//: | + | You do have an IP address, but it leads nowhere. Or resolving domain names to IPs does not work. This is usually the case, when someone™ messed with the IP configuration locally. Check whether your IP configuration is set to automatically receiving an IP address (in opposition to setting it manually) |
{{ : | {{ : | ||
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The greyed out elements are the network cards currently deactivated. If you find, that your LAN or W-LAN adapter is actually just deactivated, | The greyed out elements are the network cards currently deactivated. If you find, that your LAN or W-LAN adapter is actually just deactivated, | ||
- | When right-clicking and selecting // | + | When right-clicking and selecting // |
{{ : | {{ : | ||
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If this is the case (IP automatically chosen and ending up in this address space), you probably have no active DHCP any more, which also means, there is no internet connection possible. (But it also means, your network card //is// physically connected, your computer just does not get an IP). If this is the case, continue with [[#Maybe Someone Needs a Kick in the Pants]]. If you didn't even get an IP, continue with the next step. | If this is the case (IP automatically chosen and ending up in this address space), you probably have no active DHCP any more, which also means, there is no internet connection possible. (But it also means, your network card //is// physically connected, your computer just does not get an IP). If this is the case, continue with [[#Maybe Someone Needs a Kick in the Pants]]. If you didn't even get an IP, continue with the next step. | ||
==== Am I Actually Alone? No IP Address Received ==== | ==== Am I Actually Alone? No IP Address Received ==== | ||
- | We assume the following: You already failed to ping google, you set your IPv4 address settings to automatically, | + | We assume the following: You already failed to ping google, you set your IPv4 address settings to automatically, |
There is also another pitfall: Do you actually //have// a hardware connection? If there are no lines with //IPv6 address// or //IP address// returned from // | There is also another pitfall: Do you actually //have// a hardware connection? If there are no lines with //IPv6 address// or //IP address// returned from // | ||
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If so, try //ipconfig /renew//. This tries to get another IP address. If this fails and you are behind a router, head on to [[#Maybe Someone Needs a Kick in the Pants]]. | If so, try //ipconfig /renew//. This tries to get another IP address. If this fails and you are behind a router, head on to [[#Maybe Someone Needs a Kick in the Pants]]. | ||
- | ===== Router Accessible, Still no Internet Connection | + | ===== Hardware Issues |
==== Maybe Someone Needs a Kick in the Pants ==== | ==== Maybe Someone Needs a Kick in the Pants ==== | ||
- | If all this does not help or is not applicable, the problem may be a defective or mal-configured router or malfunctioning network hardware. | + | If all this does not help or is not applicable, the problem may be a defective or mal-configured router or malfunctioning network hardware. |
Usually (if everything worked earlier and you didn't mess around with your equipment; you didn' | Usually (if everything worked earlier and you didn't mess around with your equipment; you didn' | ||
- | If the Router | + | If the router |
- | If the router is still not reachable, you may try restarting any switch, that is used in-between (they sometimes also hang). And if that also fails, you may try using another router (if you have a spare one). If someone messed up the settings, resetting it to factory settings and configure it anew might be necessary, too. If that does not help either (or you don't have a replacement at hand), | + | If the router is still not reachable, you may try restarting any switch, that is used in-between (they sometimes also hang). And if that also fails, you may try using another router (if you have a spare one). If someone messed up the settings, resetting it to factory settings and configure it anew might be necessary, too. If that does not help either (or you don't have a replacement at hand), |
- | If it does not help, check the hardware between router and computer. Are all LAN cables in place? Are all the network switches along the way on (if there are any). Are the cables OK? (Use other cables you know are OK, to rule that one out.) Sometimes the network switches themselves act up, so you might try and restart those, too (unplugging them from the plug socket for 10 seconds should suffice). | ||
- | ==== Router Accessible but Still no Internet Connection ==== | ||
- | So your router responds and the web interface is accessible, but the internet connection still refuses to work. This is usually a problem of your ISP. You may have to live with it, until they fix it. If it does not go away, even after a few hours, try contacting your ISP on the problem. Usually it is nothing you can influence. Worst case scenario: The wiring of your home or of your carrier is defective, which requires a technician to fix the problem. Or the Router is damaged, and needs to be replaced. | ||
===== Internet Connection Up, Connecting Still does not Work ===== | ===== Internet Connection Up, Connecting Still does not Work ===== | ||
+ | ==== Is the DNS acting up? ==== | ||
So you can ping Google' | So you can ping Google' | ||
- | '' | + | '' |
{{ : | {{ : | ||
- | This should look very similarly to the other ping attempts. If you get a message like this: //Ping request could not find host www.google.com. Please check the name and try again.//, then your DNS lookup went badly. You can now try and find out, why your system cannot resolve //www.google.com// | + | This should look very similarly to the other ping attempts. If it does, continue with [[#DNS Resolves, Still no Luck]]. |
- | '' | + | If you get a message like this: //Ping request could not find host < |
+ | ==== DNS does not Resolve ==== | ||
+ | You can now try and find out, why your system cannot resolve //< | ||
- | This tries to resolve the domain name // | + | '' |
+ | |||
+ | This tries to resolve the domain name //< | ||
{{ : | {{ : | ||
- | If this works, your general internet connection setup is actually OK, but the configured DNS server to be used by your computer may be faulty. Either there is a DNS server manually configured, that does not respond any longer. If so, remove the manual configuration. Usually the DNS server to be used is provided by your router at the same time, your client gets its IP address assigned by the routers DHCP server. Or the DNS server has a problem itself. | + | If this works, your general internet connection setup is actually OK, but the configured DNS server to be used by your computer may be faulty. Either there is a DNS server manually configured, that does not respond any longer. If so, remove the manual configuration |
- | When everything works now, you are done. | + | If nothing gets resolved, head on to the next stop. |
- | If everything works just like charm (pinging < | + | If everything works just like charm for the test case provided here (pinging |
===== The Lost Phone Book: DNS Problems ===== | ===== The Lost Phone Book: DNS Problems ===== | ||
- | So you have used the standard DNS configuration, | + | So you have used the standard DNS configuration, |
{{ : | {{ : | ||
- | If there is no block with information like '' | + | If there is no block with information like '' |
- | If you do find entries here, redo the step '' | + | If you do find entries here, redo the step '' |
- | But if you prefer another DNS provider, you may of course use another one. Just be aware: Resolving domain names is a sensitive thing. Anyone who runs a DNS server will know which domains you try to connect to (as usually this is the first step before | + | **Just be aware**: Resolving domain names is a //sensitive// thing. Anyone who runs a DNS server will know which domains you try to connect to (as usually this is the first step before |
+ | ==== Am I Listening to Myself? IP Stack Damaged ==== | ||
+ | So not even your own router does answer, you get no IP and it does not seem to be the hardware. Maybe there' | ||
+ | |||
+ | There are two to three commands you can try right away, that should always work, regardless if you are connected to any network, or not. Enter one or both of the following commands there: | ||
+ | |||
+ | '' | ||
+ | |||
+ | and/or | ||
+ | |||
+ | '' | ||
+ | |||
+ | You might also try: | ||
+ | |||
+ | '' | ||
+ | |||
+ | This pings //your own computer//. All three addresses given after the '' | ||
+ | |||
+ | {{ : | ||
+ | |||
+ | If all three of these fail (no answers received or some error messages appear), then something is very wrong on your computer. It means the IP stack used by your operating system is messed up, as your own computer should //always// be reachable by itself. It is a rare instance, that this happens. If it does, you will not be able to communicate with anyone else, not on your LAN, not on the Internet. You would have to fix that problem first (e.g. re-installing your network card drivers, using your OS' recovery mechanism or let someone with a deeper understanding have a look at it). | ||
+ | |||
+ | If your computer does answer to itself, then the computer is (usually) just fine. So it's either the router, that does not answer, or you still have a configuration problem of your IP settings. It may also be possible, that you have to configure your IP connections manually. But that usually is done by someone managing your network. So you will have to refer to that person. | ||
===== DNS Resolves, Still no Luck ===== | ===== DNS Resolves, Still no Luck ===== | ||
- | There is still one other direction this can go. You can open < | + | There is still one other direction this can go. You can open //< |
+ | ===== Router Accessible but Still no Internet Connection ===== | ||
+ | So your router responds and the web interface is accessible, but the internet connection still refuses to work. This is usually a problem of your ISP. You may have to live with it, until they fix it. If it does not go away, even after a few hours, try contacting your ISP on the problem. Usually it is nothing you can influence. Worst case scenario: The wiring of your home or of your carrier is defective, which requires a technician to fix the problem. Or the Router is damaged, and needs to be replaced. | ||
+ | |||
+ | [ [[..: |
en/troubleshooting/debugging_your_internet_connection.txt · Last modified: 2022-08-10-20-30 by sw