[ltp] Cisco Wireless again

Joel Ebel linux-thinkpad@linux-thinkpad.org
Mon, 10 Nov 2003 11:41:11 -0500


I'm not sure why hotplug was called either, but for networking, not much 
is done by hotplug in slackware.  The rc.inet1 script is run, and that 
just configures the interfaces with dhcp or statically with ifconfig. 
The only wireless configuration scripts in slackware are in the pcmcia 
scripts, which hotplug doesn't call.  Nonetheless, I disabled hotplug to 
see what I could learn.  I'm still not getting an IP.

Here is what I've run and gotten as a result.  I don't have wep enabled, 
so that shouldn't be an issue.  Also, I have a linksys pcmcia card that 
works fine, so the access point is working.  I'm a bit surprised at the 
link quality as the AP is about 8 ft from me.  the linksys card has a 
quality of 92/92.  Anyway, here's what I've got.  Anyone got any 
thoughts?  Fabrice or anyone else?

Thanks,
Joel

root@amos:~# modprobe airo_mpi
root@amos:~# iwconfig eth0
eth0      IEEE 802.11-DS  ESSID:"tsunami"
           Mode:Managed  Frequency:2.442GHz  Access Point: FF:FF:FF:FF:FF:FF
           Bit Rate:11Mb/s   Tx-Power=20 dBm   Sensitivity=0/65535
           Retry limit:16   RTS thr:off   Fragment thr:off
           Encryption key:off
           Power Management:off
           Link Quality:0/100  Signal level:-102 dBm  Noise level:-256 dBm
           Rx invalid nwid:4  Rx invalid crypt:0  Rx invalid frag:0
           Tx excessive retries:0  Invalid misc:6   Missed beacon:0

root@amos:~# iwconfig eth0 essid sma
root@amos:~# iwconfig eth0
eth0      IEEE 802.11-DS  ESSID:"sma"
           Mode:Managed  Frequency:2.442GHz  Access Point: 00:06:25:24:FC:93
           Bit Rate:11Mb/s   Tx-Power=20 dBm   Sensitivity=0/65535
           Retry limit:16   RTS thr:off   Fragment thr:off
           Encryption key:off
           Power Management:off
           Link Quality:43/100  Signal level:-33 dBm  Noise level:-97 dBm
           Rx invalid nwid:16  Rx invalid crypt:0  Rx invalid frag:0
           Tx excessive retries:0  Invalid misc:33   Missed beacon:0

root@amos:~# iwconfig eth0 channel 11
root@amos:~# iwconfig eth0
eth0      IEEE 802.11-DS  ESSID:"sma"
           Mode:Managed  Frequency:2.462GHz  Access Point: 00:06:25:24:FC:93
           Bit Rate:11Mb/s   Tx-Power=20 dBm   Sensitivity=0/65535
           Retry limit:16   RTS thr:off   Fragment thr:off
           Encryption key:off
           Power Management:off
           Link Quality:43/100  Signal level:-33 dBm  Noise level:-97 dBm
           Rx invalid nwid:16  Rx invalid crypt:0  Rx invalid frag:0
           Tx excessive retries:0  Invalid misc:37   Missed beacon:0

root@amos:~# dhcpcd -t 15 -d eth0
dhcpcd: MAC address = 00:02:8a:9f:64:f2
root@amos:~# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:02:8A:9F:64:F2
           BROADCAST MULTICAST  MTU:1500  Metric:1
           RX packets:99 errors:26 dropped:0 overruns:0 frame:26
           TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
           collisions:3 txqueuelen:100
           RX bytes:9854 (9.6 Kb)  TX bytes:3468 (3.3 Kb)
           Interrupt:10 Base address:0x8000



Fabrice Bellet wrote:
> I don't know why the hotplug scripts are called in this case. They probably
> try to automatically configure the card on their own side, while you 
> also try to configure it with bcard/iwconfig manually. I don't know how 
> does Slackware perform the configuration of a wireless card, but RedHat 
> calls iwconfig repeatedly with the parameters (ESSID/CHANNEL/WEP_KEY) 
> that you fixed in /etc/sysconfig/network-scripts/ifcfg-eth1, and calls a 
> dhcp client afterwards, if needed. 
> 
> I'd suggest to try to prevent the hotplug scripts to run, at least in a
> test phase, so the only commands received by the card will be yours.
> 
>  . What are exactly the commands that you send to the card with iwconfig ?
>  . and how does each command modify the output of 'iwconfig eth1' ?
>  . do you have WEP encryption enabled ?
> 
> I use this minimalist wireless configuration script :
>      - iwconfig eth1 essid xxxxx
>          -> this should modify the ESSID field of 'iwconfig eth1' (factory
> 	    name is "tsunami")
>      - iwconfig eth1 channel NN
>          -> this should modify the Frequency field of 'iwconfig eth1'
>      - iwconfig eth1 key xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xx
>          -> this should modify the Encryption key field, moreover, the
> 	 access point MAC address should appear instead of 
> 	 ff:ff:ff:ff:ff:ff
> 
>      - then you can configure the eth1 interface (manually with ifconfig,
>        or automatically with a dhcp client).
> 
> That's all. Nothing more, nothing less.
> 
> If ifconfig reports that packets are correctly emitted, but that no packet
> is received, then you probably have a wrong WEP key, or a problem of this
> kind. IIRC, bcard also configures the wep key index to be used. There're
> several WEP key slots, and only one is used to encrypt packets. It is 
> also possible to select which slot is the active one with iwconfig,
> but this feature is quite obscur (see the key/enc[ryption] section of the
> manpage). 
> 
> Best wishes,