Not regaining ip after a disconnection

[Ron Asor]

running ubuntu 10.04
It might have been known but, I'll sum it up to you now.
After gaining a connection to a wireless ap, its all nice and shiny (from startup as example)
But,
After you disconnect from a specific network the network card some sort of freeze, and wont let you connect to other ap's even to the last one youv'e been connected to.
The method i've came across is by sudo ifconfig wlan0 down, as I thought of this and I wanted to know if its possible
to bind that command to the "disconnect all" and "refresh" buttons on the GUI, obviously when you do one of those it should reset the card and start the scan from point 0 because thats the main way it works at the moment.
so Is it possible to edit the configs of it or anyone have any more suggestions about it? because running ifconfig from the terminal after reconnecting to different networks is kinda tedious...
if any more info is needed i'll post it up, just ask.
oh, and most likely. it just somewhat of hangs at the "obtaining ip address" line, so maybe its something releated to the dhclient wrappings.

Thanks a lot.

[Ges Scott (ges-scott)]

This bug affects myself and a few friends using 10.04 Lucid and wicd 1.70.
I have tried a number of USB dongles all producing the same results.

Edimax EW-7711 Uan which uses the RT2870 chipset.
Azurewave AW-GU210 which uses the 8187 chipset.
Micronet SP907GK which also uses the 8187 chipset.

On re-boot, they connect fine to the LAST WIRELESS network, but when I try to switch to another network, whether encrypted or open, I get the unable to obtain IP address error. Using 'ifconfig wlanX down then up I eventually connect.

A point to note is that after disconnecting from a network and then attempting to connect to another one I see that it tries to obtain the IP from the last one I was connected to;

EG:

LAST connection was SKY1234 ( open or not )
NEW connection attempt to Belking54g ( open or not )

I see
'disconnecting active connections'
'SKY1234: obtaining IP address'

This then usually fails until I ifconfig DOWN then Up.

However, on a good day when the planets have aligned I can change connections quite often.

I agree that we need to have a complete flush of cache's etc when we attempt to change networks.

[Chris Cartledge (c-cartledge)]

When I reconnect to my wireless network after the router has been rebooted, then connection does not work. I have to delete the wireless network and reenter the creditials and the connecttion works OK.

This seems to be related to a similar wired problem whereby if the broadband router is rebooted, and my next linux session is soon (less than 24 hours?) then connection to the network fails. I can establish a connection by deleting Auto Ethernet and then connecting to Auto Ethernet afresh.

It looks like something is being inappropriately cached.

[Chris Cartledge (c-cartledge)]

Hi,

had not spotted the age of this report - I am using 11.10.