[lug] D-Link Wireless Card Configuration

Ed Hill ed at eh3.com
Fri Aug 23 18:02:20 MDT 2002

Hi Wade,

I'm not an expert of the following, but I'll do my best to answer.  And
I'm assuming that you're using a laptop, right?

>   - My /etc/modules.conf file has an entry "alias eth0 3c59x" which I
>     take to associating this interface with the 3c59c network
>     module.  It seems that I should add "alias eth1 wvlan_cs" is this
>     correct?

I have *no* ethernet alias entries (either "alias eth0 ..." or "alias
eth1 ...") in my laptop's /etc/modules.conf file and I think you should
delete or comment-out yours, too.  The pcmcia hot-plug stuff should do a
good job of recognizing the different chipsets used in the different
cards and this is the default behavior for a RH or KRUD install.

>   - To start the wireless network I had originally thought I needed to run
>     "/sbin/iwconfig eth1" however, this doesn't seem to work.  Evidently I
>     need to run "/sbin/ifconfig eth1" first?  The "/sbin/iwconfig" command
>     is then used simply to change the wireless parameters?

Again, the default behavior on a RH or KRUD system is that you enter the
necessary networking information for the first ("eth0") and second
("eth1") ethernet devices (to reflect whether they are static or DHCP
addresses) in the following files:


and this can be done either by-hand with a text editor or using the
graphical configuration tools.  If its a DHCP connection, then you can
ignore the resolv.conf file and just put the following in the
/etc/sysconfig/network-scripts/ifcfg-eth0 file:


and you're all set.

Note that the "first" ethernet device ("eth0") on RH and KRUD has
basically no association to either of the probably two PCMCIA (or
cardbus) slots on your laptop.  The first device is just whichever one
gets plugged in first.  And you can associate pcmcia/cardbus card
configurations with the port that they get attached to but that involves
editing the default RH or KRUD scripts.

So to start/stop the network, either plug/unplug the pcmcia or cardbus
card into either slot or issue the following commands:

  to start:  "ifup eth0"
  to stop:   "ifdown eth0"

and thats probably it.

>   - If the previous is true, then I assume I also need to create a file
>     "/etc/sysconfig/network-scripts/ifcfg-eth1" that contains the basic
>     802.11b specifications such as frequency, etc.?

In addition to the two files mentioned above, you may also need to edit
the /etc/pcmcia/wireless.opts file.  I made one tiny change to the
default KRUD 7.3 wireless.opts file:

[AAA at BBB pcmcia]$ grep -C 3 EH3 *
wireless.opts-    INFO="Cisco/Aironet example (Cisco default settings)"
wireless.opts-    ESSID="any"
wireless.opts-# To set all four ESSID, use iwconfig v21 and the same
trick as above
wireless.opts:#EH3    MODE="Managed"
wireless.opts-     MODE="Ad-Hoc"
wireless.opts-#    RATE="11M auto"
wireless.opts-#    KEY="off"
[AAA at BBB pcmcia]$ 

where I set the MODE from "Managed" to "Ad-Hoc" and I'm now able to
connect to all sorts of open wireless networks including the DIA
airport, Cafe Sole in Boulder, my neighbor's network at home, etc...

Also note: I only use "iwconfig eth0" to see my connection speed and
link quality.  I don't use it to start or stop the wireless networking.


Edward H. Hill III, PhD 
Post-Doctoral Researcher   |  Email:  ed at eh3.com,  ehill at mines.edu
Division of ESE            |  URLs:   http://www.eh3.com
Colorado School of Mines   |    http://cesep.mines.edu/people/edhill.php
Golden, CO  80401          |  Phone:  303-273-3483    Fax: 303-273-3311

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