Networking notworking sometimes, Linux vs Windows

[SWEnginerd]

Hardware: Asus P5A, AMD K6-2/400, 3Com 3C905B Ethernet card.
Software: Win98SE vs. Knoppix 3.3 11/03/03 EN (and probably other Linux distributions).
Network: DHCP

For some reason, although this card has always appeared to work under both Win95 and Win98SE, Linux doesn't always get networking running properly. There seems to be some problem with setting up the card correctly.

Last night, I tried Knoppix. It looked great except that I couldn't get out onto the net. The network I am on uses DHCP, all normal stuff, no authentication necessary to get an address or anything. Works fine every time I have booted up Windows. I rebooted Knoppix several times, and each time tried also setting up all the parameters manually -- gateway, IP, DNS. No go. Finally, I rebooted one last time to get a snapshot of how the DHCP setup came up when it failed -- and naturally, that time it worked.

The only difference in the network status info is in the hardware address for the card. When it failed, the address was being reported as "FF:FF:FF:FF:FF:FF". When it succeeded, a valid address got reported:

<pre>
eth0 Link encap:Ethernet HWaddr 00:10:5B:10:6C:54
inet addr:182.143.0.5 Bcast:182.143.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:1883 (1.8 KiB) TX bytes:1522 (1.4 KiB)
Interrupt:10 Base address:0xb800
</pre>
instead of:
<pre>
eth0 Link encap:Ethernet HWaddr FF:FF:FF:FF:FF:FF
inet addr:182.143.0.5 Bcast:182.143.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:10 Base address:0xb800
</pre>
This may also be why I have only once been able to get networking up and running on previous attempts to install Linux -- the main reason I haven't switched over to it fulltime, since I never could get out on the net with it! I tried MANY different distributions, and only ONCE got on the network (Red Hat 6.2, I think -- the one Oracle had officially approved for Oracle 8i). I had even tried different network cards, borrowing an Intel card (Linus' favorite at the time, and it worked fine at the office) from work -- which failed on my machine.

Two different cards (one known to be good with Linux, one known to work with Windows just fine -- it's working right now as I type, with Win98SE booted), multiple different Linux distributions -- what else might be triggering this problem when I use Linux instead of Windows??

 

[AkumaBao]

I'm assuming you are using a router to provide the DHCP? I guess so since the above IP is not listed on an ISP when doing a 'whois'. You mentioned using a static IP config. Can you show what you did to set the static? I'm also a bit confused as to why your are not using an internal IP network. For setting static try this if you haven't already:

Double check your /etc/resolv.conf and make sure the correct DNS servers are added.

EXAMPLE
router: 192.168.0.1

# ifconfig eth0 192.168.0.25
# route add default gw 192.168.0.1

Also, how many DHCP addresses are you leasing? If you are only leasing 1 or 2, they might still be reserved for the Windows system. Another thing could be that the DHCP/Pump config could be set incorrectly.

 

[SWEnginerd]

Thanks for the assistance. Yes, we are behind a router here. I'm not sure what you mean by "why you aren't using an internal IP network"; it's all 10/100 ethernet TCP/IP. In case you might suggest hardware changes, I'm not the network admin here, and so I am not allowed to do that.

To set the IP statically, I simply ran the "netcardconfig" script that is in the Knoppix distro (I don't know if it's now a part of the regular Linux distros or not). It just uses "xdialog" to ask some network-setup questions and then runs ifconfig, pump, route, etc. behind the scenes.

"netcardconfig" first asks if you want to set the IP using DHCP. If I picked "yes", it would try it and fail. So I tried picking "no", and it asked:
1) what the IP is
2) what the gateway is
3) what the netmask is
4) what the DNS servers are
(I think that was everything.)

The nameservers get added to resolv.conf correctly, and it runs (at least) the following commands:
ifconfig eth0 182.143.0.5 netmask 255.255.255.0 broadcast 182.143.0.255 up
route add default gw 182.143.0.1

There may be more behind the scenes that I didn't notice. The script can run "pump" in a couple of places; I didn't trace the execution path to figure out which ones got hit. The above commands were displayed in the shell window.

As far as number of DHCP-able IPs, we have at least 50 on the network, of which under a dozen are typically in use. There's plenty of space.

What I don't get is, why does it usually fail, and why did it work that one time? I didn't do anything differently; I just booted the machine from CD again. And again. And again. . . . :/ And that one time, it decided to work instead of failing.

Thanks much!