RE: Problem with WEP in one direction!?

"Jeremy Laidman" <[email protected]>
Newsgroups gmane.linux.drivers.at76c503a.user
Message-ID <[email protected]>
Thanks for your response.

> you run the atmel device in _adhoc_ mode acc. to your syslog, which is
> fine, as your peer (ssid rebel-it) announces it as an IBSS (bit1 in
> capability set, see the syslog). Furthermore its BSSID is a temporary
> one (bit1 in first byte set: 02:00:25:68:0a:64).
> With an IBSS there is no authentication stage before CONNECTing.

Thanks, now I understand.  The ssid "rebel-it" was supposed to be
obfuscated, but I didn't do a very good job, and missed a couple.
Everywhere you see "myessid" was "rebel-it" - there was only one SSID.  I'm
sorry to have confused the issue.  Below are the details again (without
alteration).

> I'd start without WEP first. Switch it off on both sides, make sure no
> other peer is running with the same SSID and try to ping. What does
> tcpdump show on both sides?

Yup, this works fine.

Now I do "iwconfig <dev> enc on" on both sides.

Enterasys says:
eth2      Wireless  ESSID:"rebel-it"  Nickname:"enterasys"
          Mode:Managed  Frequency:2.457GHz  Access Point: 02:00:03:75:76:17
          Sensitivity:1/0
          RTS thr:off
          Encryption key:1234-1234-1234-1234-1234-1234-99
          Link Quality:0/0  Signal level:-102 dBm  Noise level:-102 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:1   Missed beacon:0
eth2      Link encap:Ethernet  HWaddr 00:E0:63:83:2C:ED
          inet addr:192.168.16.1  Bcast:192.168.16.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1960 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1663 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          RX bytes:313863 (306.5 Kb)  TX bytes:300640 (293.5 Kb)
          Interrupt:9 Base address:0x100

Atmel is:
wlan0     IEEE 802.11-DS  ESSID:"rebel-it"  Nickname:"atmel"
          Mode:Ad-Hoc  Channel:10  Cell: 02:00:03:75:76:17
          Bit Rate:11Mb/s
          RTS thr=1536 B   Fragment thr=1536 B
          Encryption key:1234-1234-1234-1234-1234-1234-99   Encryption
mode:open
          Power Management:off
          Link Quality:0  Signal level:60  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0
wlan0     Link encap:Ethernet  HWaddr 00:06:F4:02:87:B7
          inet addr:192.168.16.99  Bcast:192.168.16.255  Mask:255.255.255.0
          UP BROADCAST  MTU:1500  Metric:1
          RX packets:16 errors:0 dropped:0 overruns:0 frame:0
          TX packets:54 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1248 (1.2 Kb)  TX bytes:3468 (3.3 Kb)

Atmel logs as follows, after setting enc to on:

Feb 11 10:00:23 brick kernel: at76c503.c: wlan0 param: ssid rebel-it
(726562656C2D6974) mode adhoc ch 10 wep enabled key 0 keylen 13
Feb 11 10:00:23 brick kernel: at76c503.c: wlan0 param: preamble long rts
1536 frag 1536 txrate auto excl 0
Feb 11 10:00:23 brick kernel: at76c503.c: wlan0 param: pm_mode 1 pm_period 0
auth_mode open scan_times 10 120 scan_mode active
Feb 11 10:00:24 brick kernel: at76c503.c: wlan0: state 0 -> 1 (SCANNING)
Feb 11 10:00:26 brick kernel: at76c503.c: wlan0 BSS table (curr=00000000,
new=00000000):
Feb 11 10:00:26 brick kernel: at76c503.c: 0xcf53d440: bssid
02:00:c1:91:d0:40 channel 10 ssid rebel-it (726562656C2D6974) capa x0012
rates 02 04 0B 16 rssi 23 link 0 noise 0
Feb 11 10:00:26 brick kernel: at76c503.c: wlan0 BSS table (curr=00000000,
new=00000000):
Feb 11 10:00:26 brick kernel: at76c503.c: 0xcf53d440: bssid
02:00:c1:91:d0:40 channel 10 ssid rebel-it (726562656C2D6974) capa x0012
rates 02 04 0B 16 rssi 23 link 0 noise 0
Feb 11 10:00:26 brick kernel: at76c503.c: wlan0: state 1 -> 6 (JOINING)
Feb 11 10:00:26 brick kernel: at76c503.c: wlan0 find_matching_bss: returned
cf53d440
Feb 11 10:00:26 brick kernel: at76c503.c: wlan0 join addr 02:00:c1:91:d0:40
ssid rebel-it type 1 ch 10 timeout 2000
Feb 11 10:00:26 brick kernel: at76c503.c: wlan0: state 6 -> 7 (CONNECTED)

So again, everything seems OK to this point.

> strange, there seems to be another, separate IBSS _on the same
> channel_ with the BSSID 02:62:77:01:2a:92, which the Atmel device switches
> to after been CONNECTED to 02:00:25:68:0a:64. Or the enterasys works like
> some old Prism2 firmware, which restarted every 10 seconds and changed its
> BSSID ?

There were three wifi nodes on at the time.  I've turned the third one off
to reduce any confusion. Could this have been the cause?

So now I use 'arping -c1 -I wlan0 192.168.16.1' to send one arp packet from
atmel (192.168.16.99) to enterasys (192.168.16.1):

Atmel tcpdump shows:
  10:04:39.311622 arp who-has 192.168.16.1 (Broadcast) tell 192.168.16.99

Enterasys shows:
  10:10:22.142323 ad:de:f:d0:2c:ed 4d:17:fe:ca:ba:ab 7392 68:
                         27e0 7b65 5774 0c06 c981 a457 9bc8 f011
                         6876 4170 cc69 9504 e166 0beb 54f9 3de8
                         ea02 bbd1 6517 e007 4668 e97b 7131 4d23
                         b152 3f00 0a04

I ping the other way:

Atmel shows:
  10:05:44.415681 arp who-has 192.168.16.99 (Broadcast) tell 192.168.16.1
  10:05:44.415776 arp reply 192.168.16.99 is-at 0:6:f4:2:87:b7

Enterasys shows:
  10:11:27.246214 arp who-has 192.168.16.99 (Broadcast) tell 192.168.16.1
  10:11:27.248439 0:e0:63:83:2c:ed 0:e0:63:83:3e:10 bdd7 68:
                         95e3 3574 e019 04d3 83c6 21b1 e10c 0309
                         3a24 d28c 9f51 cbef def7 ba2e 638b a521
                         f2e9 7824 d89a 9077 57bf ec35 2d30 7218
                         0332 3f00 0a04

This seems to indicate that the atmel can decrypt the enterasys packets, but
not the other way.  Either the enterasys has a problem decrypting the atmel
packets, or the atmel can't encrypt the packets correctly.  Note that the
enterasys works fine with a third device (enterasys on win2k).

Would like to see the debug output from the enterasys, but don't think
there's a way to turn it on on the wavelan2_cs driver.

Again, very sorry for confusing the issue with my lame attempt at
obfuscation.

Cheers
Jeremy
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.