Very Computer

I am planning to build a small WiFi part of my LAN.
There is an old desktop PC running SuSE, acting as a router, and it is
the one I would like to connect the USB WiFi NIC to.

I need a few questions answered before buing any NIC:
1. Is it possible to implement NAT on wireless card? So that it would
play as AP?
2. What kind of NIC would you recommend? The main requirement is that
it should work under Linux. I have heard about prism 2.5, and atheros
chipsets, but as I walk to a computer shop and ask about any NIC on
such-and-such chipset, they think for a few seconds ("what is chipset?
:)") and say "sorry, no".
3. Would it be better to buy PCI NIC than USB dongle?

Just give me names/links, whatever, please :)
I'd really appreciate it.

Regards,
Sid

Quote:> 2. What kind of NIC would you recommend? The main requirement is that
> it should work under Linux. I have heard about prism 2.5, and atheros
> chipsets, but as I walk to a computer shop and ask about any NIC on
> such-and-such chipset, they think for a few seconds ("what is chipset?
> :)") and say "sorry, no".

Quote:> 3. Would it be better to buy PCI NIC than USB dongle?

--
Timothy Murphy  
e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

Quote:>2. What kind of NIC would you recommend? The main requirement is that
>it should work under Linux. I have heard about prism 2.5, and atheros
>chipsets, but as I walk to a computer shop and ask about any NIC on
>such-and-such chipset, they think for a few seconds ("what is chipset?
>:)") and say "sorry, no".
>3. Would it be better to buy PCI NIC than USB dongle?
>Just give me names/links, whatever, please :)
>I'd really appreciate it.
>Regards,
>Sid

Regards,
Sid

There are solutions, but think about whether you want the problem in the
first place.

Quote:>Regards,
>Sid

ftp://ftp.linux-wlan.org/pub/linux-wlan-ng/FAQ
.Q: Can I use my 802.11b card as an AP under Linux?
.
.        Yes, and in the true free software fashion, there are several
.        ways:
.
.        a) linux-wlan-ng supports AP operation by using special tertiary
.           firmware on prism devices.  This firmware is not generally
.           available, however.   Contact Intersil for licensing terms.
.
.        b) The Prism2 HostAP driver uses the special HostAP mode of the
.           prism chipsets.            http://people.ssh.com/jkm/Prism2/

A typical WiFi device in this application might also connect to other WiFi
(like your laptop) in Adhoc mode.

Quote:> 2. What kind of NIC would you recommend? The main requirement is that
...
> such-and-such chipset, they think for a few seconds ("what is chipset?

Quote:> :)") and say "sorry, no".
> 3. Would it be better to buy PCI NIC than USB dongle?

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA  GPS: 38.8,-122.5

 >1. Is it possible to implement NAT on wireless card? So that it would
 >play as AP?

Yes, run the wireless device in Master mode.  Then treat the wireless
network device as if it was Ethernet, as far as routing goes.

 >2. What kind of NIC would you recommend? The main requirement is that
 >it should work under Linux. I have heard about prism 2.5, and atheros
 >chipsets, but as I walk to a computer shop and ask about any NIC on
 >such-and-such chipset, they think for a few seconds ("what is chipset?
 >:)") and say "sorry, no".

Google is your friend, regarding choice of device.

I set up a dlink 122 usb device in both master & managed mode;
however, it is 802.11b (10mbs).  I haven't used it for awhile.

I have a NetGear wg311 pci card that works fine using madwifi driver.
I have had to change my startup script a couple of times as the
madwifi driver evolves, which is a bit annoying, as the required
changes weren't very obvious.

 >3. Would it be better to buy PCI NIC than USB dongle?

A PCI with detachable antenna might work better for an AP if distance
is an issue.

 >Just give me names/links, whatever, please :)

One place to start is

http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/Tools.html

Another is [be sure to click on "compatibility"]

http://madwifi.org/

Another is http://www.linux-wlan.org [be sure to click on "compatibility"]

Good luck, Bob
--
<> Robert Geer & Donna Tomky |          ||||      We sure       ||||    <>


<>   Albuquerque, NM  USA    |      ||||       here!        ||||    <>

Quote:> I set up a dlink 122 usb device in both master & managed mode;
> however, it is 802.11b (10mbs).  I haven't used it for awhile.

Quote:> http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/Tools.html

I don't understand why ftp://ftp.linux-wlan.org/pub/linux-wlan-ng/ doesn't
have binaries available.  They point to Jean's page as an "excellent HOWTO"
but it seems very old, and doesn't have my binaries.

One would think that a major hardware vendor would at least have links to
binaries, but DLink points you to the source directory at linux-wlan.org
with no further instructions.

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA  GPS: 38.8,-122.5

Next put something in your dhcpd.conf file like:
-----------------------------------------------------
ddns-update-style ad-hoc;
option domain-name-servers      4.4.4.2;
option routers                  10.10.7.1;
option subnet-mask              255.255.255.0;

        subnet 10.10.7.0 netmask 255.255.255.0{
        range  10.10.7.100 10.10.7.250;

Quote:}

echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -P FORWARD ACCEPT
iptables -t nat -I POSTROUTING -s 10.10.7.0/24 -j MASQUERADE

I had to rebuild my kernel a couple of time before I got all the
routing stuff tweaked. But it worked OK. Good luck.

 >DLink DWL-122 is the device that I would like to use.

 >I don't understand why ftp://ftp.linux-wlan.org/pub/linux-wlan-ng/ doesn't
 >have binaries available.  They point to Jean's page as an "excellent HOWTO"
 >but it seems very old, and doesn't have my binaries.

Try http://www.linux-wlan.com/linux-wlan/

My "dlink122up" script is below - no incryption, just connects to an
access point as a basic wireless client.  It worked for my needs at
the time.  I no longer have the system I used it with.  I'm pretty
sure that I once started it in "master" mode, but didn't keep any
notes on how I did it, since I already had a 11g access point at home
& use an 11g PCI when I travel [I don't have a laptop, I lug around a
Shuttle XPC & beg use of a monitor...:-]

Good luck, HTH, Bob

#!/bin/sh
#
# Set up wireless networking for D-Link DWL-122 Wireless USB Adaptor
#
MY_HOSTNAME=`/bin/hostname`

AWK=/usr/bin/awk
DHCPCD=/sbin/dhcpcd
GREP=/usr/bin/grep
IFCONFIG=/sbin/ifconfig
LSMOD=/sbin/lsmod
MODPROBE=/sbin/modprobe
WLANCTL=/sbin/wlanctl-ng

echo "Starting wireless network for D-Link DWL-122 Wireless USB Adaptor:"

if [ -z "` $LSMOD | $GREP prism2 | $AWK {'print $1'} `" ]
then
  echo "  Loading modules..."
  $MODPROBE prism2_usb prism2_doreset=1
else
  echo "  Modules already loaded..."
fi

if [ -x $WLANCTL ]
then
  echo "  Configuring device - includes 10 second sleep..."
  $WLANCTL wlan0 lnxreq_ifstate ifstate=enable
  # the command above may not be needed everytime; however leaving it
  # in requires a sleep 10; sleep 5 doesn't seem to be enough
  sleep 10

  echo "  Joining our home wireless network..."
  $WLANCTL wlan0 lnxreq_autojoin ssid="[put ssid here]" authtype=opensystem
fi

if [ -x $DHCPCD ]
then
  echo "  Soliciting IP via DHCP for $MY_HOSTNAME..."
  $DHCPCD -h $MY_HOSTNAME wlan0
fi

echo "  You may need to set up routing."
echo "Wireless network setup complete."
--
<> Robert Geer & Donna Tomky |          ||||      We sure       ||||    <>


<>   Albuquerque, NM  USA    |      ||||       here!        ||||    <>

I don't see a binary there that is obviously compatible with the DWL-122.

At one point, I took the highest-kernel rpm from
http://prism2.unixguru.raleigh.nc.us
even though it is lower than mine.  That installed to
/lib/modules/2.4.21-32.EL instead of 2.4.21-40.EL.
Taking a chance, I copied those modules into the -40 tree.

That still gave me the message that prism2_usb was not found when I tried
the modprobe.

I decided to build from the wlan-ng source.  That fails due to unresoved
externals, first to msleep, then to a slew of other items.

Back to raleigh, where I thought I'd build from his source.  I found the
lines:
             cd /usr/src/linux-2.4.18-10
             cp configs/kernel-2.4.18-i686.config .config
             make oldconfig
             make dep

I tried that with my build of the wlan-ng modules.  I could then load
prism2_usb (I had corrected the msleep call), but p80211 failed with a
bunch of unresolved references.

So, I thought I'd go back to the raleigh down-rev modules, but the dependcy
link in the -40 kernel directory.

But now I've got older modules than the ones I just compiled, and I'm
having difficulty with the make oldconfig.

I think I just started a full kernel build, which seems like quite a waste
of time, when all I wanted was an RPM from DLink. ;-(

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA  GPS: 38.8,-122.5