I have set up MythTV and for the first time decided to run its Internet connection through a LAN in the wall. It is a simple setup connecting my MythTV box to my router using cat5 ethernet wire.

Unfortunately when trying to connect to the Internet it times out. I am unable to ping my router.

My normal home setup involves a static ip, but I am also unable to connect using dhcp.

I at first thought it had to be the way I wired up the ethernet outlets, but I have checked numerous times and then went and redid every connection on them very carefully to verify solid connections. I was still unable to connect.

Then, for kicks and giggles, I tried my wife's macbook. I tried dhcp with her mac first - IT WORKED! Then I set up the static ip like I plan to re-employ with my mythbox, and it worked as well!

I then simply unconnected the ethernet cable and reconnected it into my mythbox - not working

It is important for you all to know that when I was setting up the mythbox, it was connected directly into the same router I am unable to connect to now - with no problems. There is only one ethernet port on the computer. I am running Ubuntu Feisty. I have tried using the network manager that comes with it and also using ifconfig without resolution.

I am frustrated, especially as my wife's mac had no problems connecting - this is a first for me to be stumped on such a simple networking issue! Please save me from my embarassment

Have you checked your Linux box's firewall since the MythTV installation? Maybe MythTV changed a setting. Also check to see if the DHCP is still configured and running. There should be a process running either dccpd or dhclient. That process should be running all the time.
You could also see if the network startup code works.
That would be a good start. If none of these things are broken then we'll have to put our thinking caps on. Let's hope it doesn't come to that!

If I recall you cannot log on as root on your distribution (Ubuntu?). In that case put an sudo in front of the command to restart the network.

If you're using Gentoo I don't recall where the startup scripts are located. I tried Gentoo for a couple of weeks but found that its nonstandard configuration was not worth learning.

Thanks for your quick reply.

The thought that MythTV changing settings is a valid point. I don't think that is the case here though because I continued to use the Internet while configuring the computer before setting it up on the LAN (while it was directly connected to the router). In fact, it is now connected in the exact same way - only it connects to the wall jack which runs straight to the other jack which then connects to the exact same port on the router.

I thought the wiring through the wall was wrong - but everything worked fine with my wifes Mac!!! Why not in Linux? I have not changed any connection settings from when it worked before. By the way - I also have tried the direct connection to another computer running Linux (but Gentoo - funny how you mentioned it above ) without success. Is there an issue in Linux with multiple ethernet connections? I didn't think there was.

Any other thoughts?

p.s. 1) In Ubuntu you can also do:
sudo -i
This will let you be root.

2) Interesting take on Gentoo. I only recently started using Gentoo because I want a source distro - any suggestions on that?

Did you check to see if the DHCP client is running? Did you restart the network software in a terminal window? If so what were the results?

I am sorry for not addressing that earlier - yes it was running, unfortunately I am currently at work - I can post results when I get home.

I ran:
And to make sure I also did:
I personally wired the outlet jacks for the ethernet. I wired them so everything is straight through. I can't think why, but would it be better to make them act as a crossover cable? I read somewhere that some systems (ie routers) are able to check or work with both straight and crossover cables. I am wondering if my wife's macbook is able to do that and I need to change the configuration on one end.

Food for thought I guess. I am just bothered that I am unable to do such as simple task that I never have trouble with in Linux (hard wired) but things work in OS X. All I know for sure is that there IS a connection that CAN work but I am unable to make it work in the setup I need it to.

Sorry for babbling - just tearing my brain apart trying to think outside the box.

I solved the issue - it was an LAN line issue - nothing to do with connections. Thanks for everyone's input