Wireless without an access point

I am trying to upgrade my home network (server running dhcpd/iptables
and a laptop) to wireless. I've bought a Ralink RT2500 PCMCIA card for
the laptop and a TI ACX 111 for the server. I needed to compile a few
kernel modules from the web for them, but I'm pretty sure the drivers
are now working. Here is the iwconfig for the laptop:

ra0 RT2500 Wireless ESSID:"TEST"
Mode:Ad-Hoc Frequency=1 MHz Cell: F2:FE:57:28:28:37
Bit Rate:11 Mb/s
RTS thrff Fragment thrff
Encryption keyff
Link Quality=0/70 Signal level:-162 dBm Noise level:-256
dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

and the server:

wlan0 IEEE 802.11g ESSID:"TEST"
Mode:Ad-Hoc Channel:0 Cell: F2:FE:57:28:28:37
Bit Rate:11 Mb/s Tx-Power:60 dBm Sensitivity=0/3
RTS thr:4096 B Fragment thr:4096 B
Power Managementff
Link Quality:100/100 Signal level:-27 dBm Noise level:-256
dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

As you can see, they're both using the same ESSID and the "Ad-Hoc"
mode which I believe is necessary when you have no access point.

When I bring up interfaces using these devices, I can't get the
machines to ping each other, but something must be happening because
when I ping the laptop from the server, a load of debug messages (like
those seen here http://61.222.76.235/phpbb2/viewtopi...27f79ee13278e9)
from the driver appear in dmesg. The network settings are identical to
the working wired setup (which obviously I remove while I'm testing
the wireless). Is there some other setting that I'm missing?

Thanks,

Peter

Peter Saffrey wrote:
> I am trying to upgrade my home network (server running dhcpd/iptables
> and a laptop) to wireless. I've bought a Ralink RT2500 PCMCIA card for
> the laptop and a TI ACX 111 for the server. I needed to compile a few
> kernel modules from the web for them, but I'm pretty sure the drivers
> are now working. Here is the iwconfig for the laptop:
>
> ra0 RT2500 Wireless ESSID:"TEST"
> Mode:Ad-Hoc Frequency=1 MHz Cell: F2:FE:57:28:28:37
> Bit Rate:11 Mb/s
> RTS thrff Fragment thrff
> Encryption keyff
> Link Quality=0/70 Signal level:-162 dBm Noise level:-256
> dBm
> Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
> Tx excessive retries:0 Invalid misc:0 Missed beacon:0

The signal and noise levels are impossible: they are both 100 to 150 dB
too small. Also, there is no link: quality = 0/70.

> wlan0 IEEE 802.11g ESSID:"TEST"
> Mode:Ad-Hoc Channel:0 Cell: F2:FE:57:28:28:37
> Bit Rate:11 Mb/s Tx-Power:60 dBm Sensitivity=0/3
> RTS thr:4096 B Fragment thr:4096 B
> Power Managementff
> Link Quality:100/100 Signal level:-27 dBm Noise level:-256
> dBm
> Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
> Tx excessive retries:0 Invalid misc:0 Missed beacon:0

The signal is possible, though on the high side. The customary receive
levels are -40 dBm to -70 dBm, and the noise levels near -90 dBm.

The transmit power is ridiculously large: +60 dBm = 1 kW.

It seems to me that your WLAN card drivers and iwconfig do not match.

HTH

--

Tauno Voipio
tauno voipio (at) iki fi

Peter Saffrey wrote:

> As you can see, they're both using the same ESSID and the "Ad-Hoc"
> mode which I believe is necessary when you have no access point.

It certainly is not _necessary_ to have both in Ad-Hoc mode,
as my desktop is in Ad-Hoc mode and my laptop in Managed mode,
and they work together fine (Avaya and Orinoco cards).

--
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