Ubuntu 12.04 internet connection fail
 

The only thread I have read that seems to cover my problem recommends going into my terminal and changing dns=dnsmasq to dns=dnsmasq-base. I am reluctant to do this before I get more advise. Here's my problem. My ISP either purposely disabled my modem to force me to lease a newer model, or I somehow changed my system settings and lost my internet connection. It took my ISP a full week to conclude that I needed a new modem. They are clueless about Linux, however, they assure me that my new modem is Linux compatible. I got my modem on Thursday and it took until yesterday (Sat) to get it properly configured. I don't have the 12.04 guide book, so I printed instructions to manually set-up my network.
My current situation is this. My modem is "all green" and evidently properly configured, my computer says my wired connection is "on". I have a DSL ethernet connection, but I can't connect to the internet.

My questions:

How likely is it that, despite my ISP's assertions, my modem is not Linux compatible?
How do I confirm that my network settings are correct?
If I install another version of Ubuntu, is this likely to automatically correct my settings if they are wrong?
If I take my modem and desktop to a linux shop can they diagnose the problem or does my modem need to be conected to my home phone jack to be evaluated?
I entered only 2 different numbers in my system settings-my IP address is listed in 3 different boxes and 255.255.255.0 is in one of the other boxes(can't remember what the 255. number is called.)
I hope this is enough info and the right questions to ask. Sunday is a baaaaaaad day to have tech problems!

It sounds like you have at least started to configure a static IP. Do you know the local IP address of your router? Have you tried pinging it? Have you tried going back to DHCP and connecting? Without sounding strange, how are you connected now?

Also, do you have a modem and a router, or are they combined into one device? What modem is it you have?

I am on an ethernet modem. Does that answer?

If it's Ethernet then I don't see how it can be incompatible with Linux, although someone may correct me on that. You need to determine your network settings. DHCP is the most common method of setting the network up out of the box, assuming we're talking residential here. Did you use network-manager or a similar GUI to configure your network, or did you edit a file located in /etc/network/interfaces?

To answer your questions directly:

I would say unlikely, it's easier for them to just brush you off by saying it's incompatible than saying it is compatible.
If you can ping your router/gateway or ping 8.8.8.8 (Googles DNS) then it's working.
It's reset your settings back to the default ones, which almost certainly will be DHCP.
If they get it working at thier shop, that's great, but that might not help you when you get it home...
255.255.255.0 is the subnet. This makes me think you have started to setup a static network. Where did you get the other two numbers from? Did your ISP tell you to put them in?
Totally agree. :)

If you connect to your MODEM using an ethernet cable then it's unlikely it is not going to work with Linux.
I am not sure exactly what the fix you mention at first would achieve but I don't see anything that would set off my "Don't do it!" alarm -- if a small configuration change will work why not try it?

Generally, to connect a computer to the internet one plugs in the MODEM and attaches it to the phone line then connects a computer to it using an ethernet cable and goes to the configuration page. Once there the only things you ought to have to change are the WAN settings and any passwords for internet access which you should get from your ISP -- local IP addresses and subnet mask (the 255.255.255.0 thing) you should not have to touch.
This is something you have to set up in situ since your MODEM has to communicate with your ISP in order to gain access to the internet -- you then connect a computer to it and that gets to the internet through the MODEM. Your computer will generally not need any setup to connect to the internet once your MODEM has been set up correctly.

I openned my network settings and did a manual entry of my IP etc. according to intstructions that I printed from a computer at my job. The photo of the network settings page in the instructions looked just like mine and I entered the addresses exactly as instructed. Incidentally there was no space for entering my internet username or password, which I expected to have to enter. I didn't enter the info in the wired tab. I did it in a different tab that I don't remember to name of. It was something like ipv4 or something. The instructions also had me enter the terminal to see the addresses listed but didn't tell me exactly what it was supposed to say in the terminal. Sorry if this is vague.

The probably problem here is even if you copied my network settings, then it probably wouldn't work on your network, as my network is configured differently to yours.

If you open up a terminal, type in and copy and paste what it says?

My ISP gave me the IP # and the subnet mask #, which I entered in the network settings

I am not at my computer right now. Can we talk on the phone when I get home? I live in Portland, OR.

When you get home, take a note of what make and model of modem you have. This will give us a much better idea of how exactly you are connecting to the internet and also the default settings of the device. Once we know if you're using it as a router or connecting directly as a modem, we can determine exactly how the router should be configured for your computer. The reason I was suggesting doing that ping is because it sounds like you have set it up for a static IP on a network but you didn't mention anything about DNS settings. Whilst this may be held in your router, I cannot be certain of this without knowing your router settings. If you can ping Google's DNS servers, then you just need to add them (8.8.8.8) to your DNS entry within the network-manager. It will be listed under DNS servers:

Whilst I'd love to try and guide you over the phone, it would be a very expensive phone call for you to call Germany and my partner wouldn't be too happy about me talking to someone when they're trying to sleep. ;)

You say "a terminal". I am only aware of one terminal thus far. Do I need to open a specific terminal or one of many?

GERMANY? OMG! I don't know exactly what a router is. My modem is connected directly to my computer and my landline phone jack. Is a router part of the modem (built in) or is it a separate piece of hardware plugged into the computer?

If I am not mistaken, I believe the number I entered in the DNS space was the same number as the IP address. But I am not possitive. I would have to look at my network settings to be sure. Thank you for answering all of my questions thus far. I should go back home so I can give "someone" the info they need to help me. Can you tell me if I would find all of this information in the 12.04 manual. I have an outdated Ubuntu manual that isn't very helpful.

If my modem is connected directly to my computer and phone jack, would there be a router involved? I don't know exactly what a router is and if it is involved in my internet connection.