Checking an Internet Connection

[anonprivate]

The other night I could not access the Internet.

According to my wi-fi icon I was connected to my ISP. But why my ISP connected to the Internet?

Is there a method that I can use to check if my ISP is connected to the Internet, or if there is a fault at the ISP preventing connection?

Thanks

[Teunis]

This is a late reply but it might help someone.

Linux has quite a few networking tools, for what you want you should probably use ping, traceroute and/or mtr.

The command for ping to check the connection with google.com:

ping google.com

This will not tell you much except you have a connection and how fast it is or don't have a connection.
You stop it with Ctrl+C

mtr gives more information about the path:

mtr google.com

You stop it with a q.

In your case you should probably try ping and mtr with the server of your provider as address, like with my provider I'd do something like:

mtr shell.xs4all.nl

Mine looks like this:
My traceroute [v0.85]
W520-15 ( Sun Sep 13 22:51:08 2015
Keys: Help Display mode Restart statistics Order of fields quit
PacketsPings
Host Loss% Snt Last Avg Best Wrst StDev
1. fritz.box 0.0% 2 3.4 3.3 3.2 3.4 0.0
2. lo0.dr14.d12.xs4all.net 0.0% 1 31.5 31.5 31.5 31.5 0.0
3. 1313.ae3.xr3.3d12.xs4all.net 0.0% 1 29.1 29.1 29.1 29.1 0.0
4. 0.ae2.xr4.1d12.xs4all.net 0.0% 1 28.7 28.7 28.7 28.7 0.0
5. shell.xs4all.nl 0.0% 1 30.7 30.7 30.7 30.7 0.0


The first line should be your modem/router, then follow a few lines with network gear until you reach the actual server you are accessing.

man ping

and

man mtr

will give you information about the various options those commands have.

[logan01]

Try Ethernet cable?

[GreyGeek]

The lights on your cable modem will tell you if the connection between it and your ISP is down. The lights on your wifi modem will tell you if you are getting a good connection to your cable modem.

as always, start with the hardware, including the cables and connectors. Cables can knot up, changing their electrical properties. Connectors can corrode or dirt work its way between contact points with micrivibrations, etc...