Hi

I've been having a lot of fun with wireless promiscuous mode on my N900 but on two or three occasions now, that promiscuous 'magic' has vanished and no amount of re-boots or $sudo ifconfig wlan0 promisc can recover it. All I could pick up were multicasts. The only way to recover it has been to re-flash.

Now, the other day when everything was working like a charm I foolishly fiddled with a couple of things. Nothing major, if I remember correctly it was to switch off my Skype status which I rarely used, and also to load a couple of updates that were flashing in the top status bar (recorder and 3G/2G switcher applet). Suddenly the magic was lost and all I could see were multicasts. I then noticed TCPDUMP gave the following message which I dont remember seeing before - but I may be mistaken and this is not relevant:

Nokia-N900:~# tcpdump -i wlan0
tcpdump: WARNING: can't create rx ring on packet socket 3: 92-Protocol not available
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on wlan0, link-type EN10MB (Ethernet), capture size 96 bytes

OK, so I have a backup, why not just re-flash and get the promisc magic back? Well I've done so now twice and I cant seem to get it back. What has happened? BTW I only flash the combined BIN file as this leaves the rest of the N900 (photos etc) in tact. I dont really want to do a complete factory reset.

Does anybody out there understand the workings of tcpdump and promisc mode sufficiently well to help? Is it some kernel module getting screwed up? I only use the standard Nokia kernel as it is compatible with Joikuspot.

How do I get the promisc magic back? Help please!

N900 has some form of promiscuous mode without power kernel? I could've sworn you could only get the monitor aspec on power kernel and injection only on power kernel with lxp's drivers...

I remember in the early days people were messing with the N900 trying to get monitor mode working. I don't think it ever worked reliably on the N900's stock firmware. How badly do you need JoikuSpot, vs. the free wifi hotspot program that works with power kernel?

Thanks for the response. I was not aware of the free hotspot - I'm more than happy to give it a try if using the advanced kernel will give me promiscuous mode back.

Just to be clear, I'm not really interested in monitor mode, which will allow an un-associated wireless device to read the wifi beacons as well as any actual data packets.

What I want is promiscuous mode. If I am associated with a wireless network as device A, and the wireless network also has a unicast conversation going on between B and C, then I want to be able to read those unicast packets, e.g. with Wireshark. I've had it working just as described in this link and then, suddenly, it is gone and all I can see is multicasts.

http://www.knownokia.ca/2010/04/usin...d-profit.html#

I found that neither flashing the enhanced kernel, nor flashing back to the stock Nokia kernel made any difference to promisc mode.

However, I have now re-flashed from the USB cable and this time, I was pressing the U key as I connect the USB cable as per the wiki instructions. Pleased to report that this time promisc mode has been restored! As a side note, I think I failed to press the U key during the last couple of re-flashes. Does that really make a difference? Perhaps it does!

I would conclude that it is not a kernel issue, but more likely something to do with a driver for the wireless chipset that gets replaced without warning during some package upgrade. I hope to work out the offending package or at least work out a way of taking a backup of this precious config that can be restored without a re-flash. Once again, any help from people who actually understand this stuff would be most welcome!