[ltp] strange behaviour of wireless

[Arno Trautmann]

Richard Neill wrote:
>>>
>>> One thought: do you have NetworkManager (the system service) running? It
>>> does things in the background that can sometimes be strange...if you are
>>> manually configuring with iwconfig/dhclient, you may want to check it is
>>> off.
>>
>> No, at least I think it is not running. But to be sure, how can I
>> check it?
>
> /etc/init.d/network-manager status
> or
> ps aux | grep -i networkmanager

$  ps aux | grep -i networkmanager
root      4500  0.0  0.0   8244   968 pts/0    S+   18:50   0:00 grep

> If Network manager is NOT running, you might try using it: the latest
> version isn't bad (start the gnome "nm-applet" for a gui, and read logs
> which are sent to syslog).

zsh: command not found: nm-applet
(using fluxbox)

>>> You might try one other distro (eg Ubuntu's) live CD (or live USB stick)
>>> - simply as a way to eliminate whether this is more likely a software or
>>> a hardware issue.
>>
>> Will do. (As the X61 doesn't have an optical drive, I have to use anUSB
>> stick which I never succeeded so far in making bootable …)
>
> Try using: http://unetbootin.sourceforge.net/

Will do.

>>>> • Ok, so far I'd just say “stupid Linux, doesn't work” (or rather
>>>> “stupid user, doesn't configure correctly”). But now comes the part
>>>> that
>>>> doesn't make any sense to me: Whenever I connect to my home network, my
>>>> rommates cannot. In fact, their machines don't even see the radiation
>>>> any more. As soon as I disconnect, they have excellent signal strengths
>>>> and connect immediately. When I reconnect, they're out, again.
>>>>
>>> Wireless g/b issue? Is it possible that you or they are on 802.11b and
>>> that this is making the access point switch modes. (Or, for that matter
>>> g vs a)?
>
> I'm beginning to be suspicious of your access point, rather than the
> Linux side. Is it possible that you are causing it to crash?

Then I wouldn't have access, too, would I?

>  Or perhaps
> you are using wireless "a" which is causing the AP to switch away from
> support for wireless "b" devices, thereby cutting off your roomates?

Maybe? … I'll try to check what my roommates see if they are connected. 
But that seems like a reasonable explanation.

> [Is anyone using equipment older than ~ 4 years?]

The machines should all be around that old, maybe 5 years.

> Does the AP have any form of logging or web control panel? Is it a
> reasonably recent (this year) model, or a much older one? Is it a
> "cheap" AP or not?
> [I hesitate slightly here: some £15 APs are actually much better than
> some £50 APs: so cheap refers to quality not to price!]

I'll check the model and write you what it is.

>> At the moment (at the university) I'm on a 2.462 GHz connection. I'll
>> check tonight what channels are used at home. (If that is the
>> information you need.)
>
> Does it work reliably and repeatably for you on the university connection?

The connection is ok and mostly reliable, but recently I have problems 
with the vpn that is used. vpnc throws something like
“either "to" is duplicate or "ipid" is a garbage”
I then have to reboot or wait about 30min until I can connect again. But 
the behaviour changes daily, sometimes I lose the signal after a few 
seconds, while mostly I can stay for hours. But that may rather be an 
access point problem.

cheers
Arno