Strav's blog

OK - here is one of those situations that make administering a system so frustrating. I've been moving (too slowly for my taste) my wireless network from a MAC filtered based system (way too easy to spoof) to a WPA2 encrypted network (currently the most secure publicly available wireless security). This is a breeze in windows - just get a card that has WPA2 drivers. Under Linux, however, it isn't quite so straightforward. I chose to go with wpasupplicant as it seemed to be the easiest to set up. I've replaced the internal mini-pci cards in my laptops with an intel 2200bg which supports wpa2 via the ipw2200 module. I initially began setting this up with one of my omnibook 6100's and was patently unsuccessful. So, I decided it might be easier for something a little more standard and settled on a Cisco AIR-CB21AG pcmcia card. This is supported by the madwifi drivers and didn't take too long to set up. Once I had a working WPA2 config with the pcmcia setup, I was able to leverage on that to set up one of my 6100's. The real fun began when I tried to set up the second 6100. I could not get the driver to automatically load at boot. If I checked with iwconfig, the card was always defaulting to the unsecured SSID. Wpasupplicant worked, and I could manually switch it to the WPA2 network, but something obviously wasn't quite right. In any case, after a couple of weeks of changing config files, searching for differences between the two 6100's and lots of package management (comparing between the two systems), I finally found the problem. There is a line in /etc/network/interfaces that allows for hot plugging (fairly important for pcmcia, somewhat less so for the internal network). The wireless stanza I had on the troublesome system was:

allow hotplug wlan0
iface wlan0 inet dhcp
wpa-driver wext
wpa-conf /etc/wpa_supplicant.conf
test-missing-cable please


but what it should have been is:

allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-driver wext
wpa-conf /etc/wpa_supplicant.conf
test-missing-cable please


Note the - in the allow-hotplug line. This was the little bugger that had me stopped in my tracks for weeks. Grrrrr.....

Now that the system is finally bringing up the wireless automatically, it's time to get cracking on the ifplugd scripts....

The debian default setup for SNORT has the daily summary mail sent out from 'root'. While accurate, this is not ideal when it comes time to file (for some reason, it's easier for my brain to locate the 'snort' folder when I'm looking at mail from 'snort' instead of mail from 'root'). In any case, modify the /etc/cron.daily/5snort file and add 'echo "From: Snort <root>";' after the 'echo "To: $DEBIAN_SNORT_STATS_RCPT";' section.

I had a problem recently trying to use rsync on a WinXP system across drives. The ':' is significant in rsync so it doesn't work with the windows drive lettering scheme. The following line shows how to use the cygwin drive addressing to make it work.

C:\WORK\* --> /cygdrive/c/work/*

OK - Here's a solution for another issue that has been bothering me. Opening MS help files (.CHM) over a network. What I've seen is that the file opens, displays a tree in the left pane but refuses to display content in the right pane.

The problem is apparently with IE security settings. The following registry file has generally fixed it for me.

chm network registry fix

Occasionally I get errors during the apt-get upgrade process. Here's a simple solution to one - the 'file or dir already exists' error:


dpkg: error processing /var/cache/apt/archives/package (--install):
  trying to overwrite 'file/dir', which is also in package other_package

Errors were encountered while processing:
  /var/cache/apt/archives/package


So - here's what to do:



dpkg -i --force-overwrite /var/cache/apt/archives/package