Can't Ifup Wlan0 After Ifdown

SuSE 10.2, fully updated. Gateway MP8708, Intel 3945ABG. Router is a D-Link WBR-2310. I'm on channel 11, and I use only the 802.11g mode, with WPA2 PSK, and an AES passphrase. I've downloaded and installed the iwl3945 driver along with the mac80211 and iwl ucode, as well as updated iptools. Everything seems to be working just fine.

Right now I've got the wireless interface set up for ifup manual start. Onboot works fine too; I've got it set up for manual for troubleshooting purposes (my guess was that I'd be able to identify what was causing it not to come back up more easily if I was doing it manually- silly me). I don't like the NetworkManager; it's yet another layer of complexity making it harder to operate. I might be wrong about that, and please feel free to tell me so if I should be testing it.

I generally use wireless, because I like to drag the box around the house wherever I am and use it without having to worry about cabling, but occasionally I take it up to the office and connect my wired LAN; it's a "Gateway 2000," but it runs off the e100 driver. It also works fine. I use it with ifplugd.

The wireless and wired networks are on different subnets; there's no obvious way to turn the wireless router into a bridge, so I just went with different subnets and let it go at that. It's easier to configure it anyway, considering I've got a homogenous Linux and Windows environment on both wireless and wired networks. So to connect to wired, when I'm already connected to wireless, I ifdown the wireless and let ifplugd set up the wired networking. This works fine.

Here's the problem: once I've downed the wireless, I can't get it to come back up. If I iwconfig it to list the settings, it says it has no encryption keys (they're all blank). If I iwconfig the encryption key with my passphrase, it still won't come up, and the encryption key is different from the one I get when I first bring it up after a reboot. I have the WIRELESS_WPA_PSK setting in the ifcfg-wlan-<PCI ID> file set to the passphrase for my wireless network, and in any case, the first time I ifup it, it works fine. What the heck is going on here?

OK, one additional piece of information: if I unload the iwl3945 driver with modprobe -r after the ifdown, then load it again before the ifup, it works fine. So I've got a viable strategy, but it seems kind of clunky; I'm guessing some kak is screwing up the driver module. Anybody got an idea what that might be? Or what I might look at to see where the problem is so ifdown/ifup will work?

OK, so I just decided not to fight city hall; here's a solution:

#!/bin/bash
if [ `basename $0` = wireless-down ]
then
**ifdown wlan0
**if modprobe -l iwl3945 | grep iwl3945
**then
****modprobe -r iwl3945
**fi
elif [ `basename $0` = wireless-up ]
then
**if modprobe -l iwl3945 | grep iwl3945
**then
****modprobe -r iwl3945
**fi
**modprobe iwl3945
**ifup wlan0
else
**echo "This script must be called as wireless-down or wireless-up. Please try again."
fi

Add this as "wireless-up" to /root/bin, and make a link to it named "wireless-down." You'll need to add the x permission for the owner. To run it as an ordinary user use sudo -i (you'll need to acquire root's environment to run it).

ETA: Still interested in the answer to how to figure out what's going on with the module, though; this is kind of clunky. If anybody knows a good way to figure it out, please let me know here.

just a thought, when you want wireless, do you ifdown your wired ?

just a thought, when you want wireless, do you ifdown your wired ?
[/b]

I use ifplugd, if it's not plugged in it's not up. But yes, I checked. The script above is working fine; it's clearly something to do with the driver.

ETA: Thanks nevertheless for sharing your thought. It was worth checking.

Script is still working fine. The only two times it hasn't worked, my Vista box didn't connect either and I wound up resetting the WAP. So this is a viable solution to the problem.