Setting up cablemodem...

[Doug Slattery]

Howdy folks,

I've just setup my machine to dual boot windows and linux (fedora 8). I'd like to connect it to the internet (which works fine from the windows side), but when linux boots, networking starts ok, but DHCP fails. I have a US Robotics 8004 firewall connected to a Toshiba PCX2500 cablemodem and the isp is Oceanic/Time Warner Cable (if that matters...).

I've done some googling, but it hasn't given any useful results.

Anyone have any links to howto's, faq's, etc.? I already know about securing the system issues, but just need to get connected before worrying too much about that.

Aloha & Happy New Year!
Doug

-- Nothing is impossible if I'mPossible

[Diego Freniche]

<Disclaimer>
This info apply to Debian Linux, and it should work more or less on RH / Fedora, buy YMMV.
</Disclaimer>

Test your IP stack is working. Open a console, an become root using:

$ su    

When root passord is entered, your prompt will change to #
Then, write:

# ifconfig    

You will see information for every network interface installed in your machine. It tipically starts with interface lo (local) AKA 127.0.0.1. eth0 is your first ethernet card, eth1 the 2nd, etc. Wifi cards must appear also.

Can you see eth0 here: OK.
If not, your network card kernel module (is not exactly the same, but view it as a "driver") is not loaded. Post here and will try to help.

If you can see the network card, try using a graphical config program or, better, go to /etc/network and assign yourself an static IP. Edit file interfaces as root:

# kate /etc/network/interfaces    

It should look kind of:

allow-hotplug eth0
auto eth0
iface eth0 inet static
address 192.168.109.161
netmask 255.255.0.0
gateway 192.168.100.3

Obviously, you will have to adjust IP ranges, gateway Ip and so on.
Restart network using: /etc/init.d/networking restart.

[Doug Slattery]

Thanks for the feedback Diego,

Test your IP stack is working.

The local network and ethernet is ok. DHCP is the problem. It fails to load. Since there was special s/w that had to be installed on my Win2k side, I figured there was something special it did beyond configuring DHCP that needed to be done to Linux too.

If you can see the network card, try using a graphical config program or, better, go to /etc/network and assign yourself an static IP.

I've thought about trying a static ip using the current settings on the Win2k side. This would only be a test and/or temp solution as the isp reassigns addresses periodically. If that works, then it's probably a DHCP configuration problem on the Linux end. I'll let you know how it goes.

Aloha,
Doug

-- Nothing is impossible if I'mPossible

[Diego Freniche]

Time to think...
If you boot on the Windows side, everything is OK, DHCP works, you get an IP address from your US Robotics 8004 Router, and life's good :-)
So I assume:
- dhclient in Windows works OK.
- you have DHCP server active on your US Robotics 8004, and you can log into the router and see which computers have obtained as IP.

If that fails in Linux, but setting a static IP works, then it's one of two:
- you have connected at the same time the ethernet cable AND your wifi card (if the machine is a laptop). Disconnect wifi and try only with ethernet UTP cable.
- your /etc/network/interfaces is not correctly configured. Try:

 
auto eth0
iface eth0 inet dhcp

Save, and then:

 /etc/init.d/networking restart   

Hope this helps

[Doug Slattery]

Thanks Diego,

This is just an FYI on the progress, not much else... It's not working still. BTW, my file is /etc/sysconfig/network/ifcfg-eth0 (or close to that ).

The static ip didn't work. I was able to assign an address (ifconfig confirmed this), but couldn't get anything to go out.

I had a buddy who is more knowledgeable than I on the later linux releases help for a while. He was stumped too. We even tried bypassing the firewall and connecting straight from the pc to the cablemodem - no dice.

I'll keep googing for a while. I have a feeling something might be interfering with dhcp, but I'm not sure what at this point. I have the linux firewall and ip6 disabled. Not sure what else it could be.

Oh, there is no wi-fi, just straight 10/100 ethernet.

Aloha,
Doug

-- Nothing is impossible if I'mPossible