Internet Connectivity

David Rush ky0dr at earthlink.net
Mon Oct 15 13:16:49 CDT 2001


Chris:

I'll try to help where I can.  I have no personal experience with either 
Mandrake or @home, but for "the basics" it shouldn't matter.

I assume that you've got an Ethernet connection between your Linux box and 
your cable modem.

Is there an LED on either of your Ethernet cards that indicates "link" when 
it's plugged into the cable modem?  If so, it should be on when a good 
cable is properly plugged in (to both the computer and the cable modem), 
and go off when you unplug the cable.  Does the cable modem have such an LED?

If link LEDs indicate that everything is "good", that suggests that the 
Ethernet layer is working, at least on the wire.

Now let's see if the IP layer is "up" on your Linux box.  From a shell 
prompt, type "ifconfig -a" (without the quotes) and hit return.  If it 
cannot find the "ifconfig" command, you'll need to specify the path to 
"ifconfig" (on my RedHat box it's at /sbin/ifconfig).  You can use "find" 
to find the file, like this:

[david at bubbles david]$ ifconfig
bash: ifconfig: command not found

[david at bubbles david]$ find / -name ifconfig -print 2>/dev/null
/sbin/ifconfig

The ifconfig command should give you something like this:

[david at bubbles david]$ /sbin/ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:C0:4F:04:2C:AE
           inet addr:192.168.12.247  Bcast:192.168.12.255  Mask:255.255.255.0
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:9216835 errors:1 dropped:0 overruns:4 frame:1
           TX packets:496068 errors:0 dropped:0 overruns:0 carrier:0
           collisions:2737 txqueuelen:100
           Interrupt:11 Base address:0xdc00

lo        Link encap:Local Loopback
           inet addr:127.0.0.1  Mask:255.0.0.0
           UP LOOPBACK RUNNING  MTU:3924  Metric:1
           RX packets:283 errors:0 dropped:0 overruns:0 frame:0
           TX packets:283 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0

You're looking for the "eth0" section, which is the InterFace CONFIGuration 
(thus ifconfig) for your Ethernet card.
If you don't have an "eth0" section similar to above, then your Linux box 
isn't seeing your network card.

If you do have an "eth0" section, but the "inet addr" (IP address) is all 
zeros (0.0.0.0), then there might be some DHCP problem (or the cable modem 
isn't working correctly - I'm assuming that @Home uses DHCP).

Try the above stuff and let us know what you find out.

David

At 10/14/01 09:09 PM -0500, you wrote:
>Hi,
>
>I've been trying to get a Linux machine to connect to the internet now for 
>a couple months, reading FAQ's and man pages trying to find the commands 
>to get things to work the way I need it to.
>I've not had much luck, partially because a lot of the FAQ's are over my 
>head.  I'm using @Home for my ISP, and running a Linux Mandrake 7.2 
>machine.  I was having some troubles getting my
>3Com card to be recognized by my cable modem and dug out an old SMC card I 
>had tucked away in a closet somewhere and that seems to at least be 
>recognized by the modem.  I'm not sure
>what my problem is, I assume I need a hostname to get DHCP to do it's 
>thing, but I don't know what the hostname would be.  Then again I may be 
>off the mark altogether.
>I'm sorry for such a limited amount of information, any help in laymans 
>terms would be greatly appreciated.
>
>Chris
>
>
>
>




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