Comment 10 for bug 459732

I am seeing similar things.

$ lsb_release -rd
Description: Ubuntu lucid (development branch)
Release: 10.04

$ uname -a
Linux ubuntu 2.6.32-21-generic #32-Ubuntu SMP Fri Apr 16 08:10:02 UTC 2010 i686 GNU/Linux

$ lsusb
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 003: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
Bus 004 Device 002: ID 046d:c03d Logitech, Inc. M-BT96a Pilot Optical Mouse
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 03f0:3611 Hewlett-Packard PSC 2410 PhotoSmart
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 413c:2003 Dell Computer Corp. Keyboard
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 006: ID 0846:4260 NetGear, Inc. WG111(v3) 54 Mbps Wireless [RealTek RTL8187B]
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

What I observe in syslog is the card deauthenticating from the wireless network,
every 5 minutes or less, with 'Reason: 4), e.g.

Apr 19 07:45:10 ubuntu kernel: [149791.540484] wlan1: associated
Apr 19 07:45:10 ubuntu kernel: [149791.546125] ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
Apr 19 07:45:13 ubuntu dhclient: DHCPDISCOVER on wlan1 to 255.255.255.255 port 67 interval 6
Apr 19 07:45:13 ubuntu dhclient: DHCPREQUEST of 192.168.13.12 on wlan1 to 255.255.255.255 port 67
Apr 19 07:45:20 ubuntu kernel: [149801.892009] wlan1: no IPv6 routers present
Apr 19 07:48:49 ubuntu kernel: [150010.760375] wlan1: deauthenticated from 00:09:5b:dd:8f:3a (Reason: 4)

This appears to be some kind of activity timeout, if the code is an official 80211 code.
The message appears to be coming from
/usr/src/linux-source-2.6.32/net/mac80211/mlme.c
The timeout seems to be defined in
/usr/src/linux-source-2.6.32/drivers/net/wireless/hostap/hostap_ap.c

This is weird because I am sending syslog packets (udp) to this machine,
ie there is wireless network traffic directed to that interface, every 10-60 seconds.

I set up a cron job to do an outbound ping (box -> router) every 4 minutes.
Made no difference.

I changed the cron job to do an ifdown wlan1; sleep 5; ifup wlan1; every 4 minutes.
This at least kept the interface up most of the time, but I still got (Reason: 4).

I don't have network-manager or wicd installed. I do have wpasupplicant but I am
using wep, so that should not matter, correct. /etc/network/interfaces contains:

auto wlan1
iface wlan1 inet dhcp
  wireless-ap any
  wireless-essid mylittlenet
  wireless-key d00b-ed00-6b
  wireless-mode managed

I installed linux-backports-modules-wireless-lucid-generic, made no difference.

The normal mode for this system is to sit quietly under a desk with nobody logged in.
I don't know why that should matter. I had a deauthentication while collating this report.