Problem with ifupdown script
Jay Ridgley
jridgley2 at austin.rr.com
Mon May 31 12:45:53 UTC 2010
Josef Wolf <jw at raven.inka.de> wrote:
> Date: Sun, 30 May 2010 21:55:28 +0200
> From: Josef Wolf <jw at raven.inka.de>
> Subject: Problem with ifupdown script
> To: ubuntu-users at lists.ubuntu.com
> Message-ID: <20100530195528.GA15925 at raven.wolf.lan>
> Content-Type: text/plain; charset=us-ascii
>
> Hello,
>
> I want to configure my laptop to automatically use eth0 or wlan0 depending
> on whether the network cable is plugged or not.
>
> I use traditional network configuration instead of NetworkManager because
> I configure my systems automatically with a system similar to cfengine,
> and networkmanager's interactive configuration doesn't play well with
> automatic configuration.
>
> So I have put this into /etc/network/interfaces
>
> auto lo eth0 wlan0
> iface lo inet loopback
>
> iface eth0 inet dhcp
>
> iface wlan0 inet dhcp
> wpa-conf /var/cfsvn/conf/wpa_supplicant.conf
>
> and installed ifplugd to configure/deconfigure eth0 when the cable is
> plugged/unplugged. Then, to configure/deconfigure wlan0, I decided to
> use the ifupdown mechanism:
>
> #! /bin/sh
> # this is /etc/network/if-up.d/myifup
> [ x$IFACE = xeth0 ] && ifdown --force wlan0
> exit 0
>
>
> #! /bin/sh
> # this is /etc/network/if-down.d/myifup
> [ x$IFACE = xeth0 ] && ifup --force wlan0
> exit 0
>
> The problem is that this mechanism works only every other time. When I
> unplug the cable and plug it again, it works. When I unplug/plug again,
> it doesn't work (wlan0 don't come up). Then I unplug/plug again and it
> works. Again unplug/plug and it don't work. and so forth.
>
> Any ideas why wlan0 come up only every second time? Any hints?
>
>
>
Josef,
I am by no means an expert, however, could it be that the interface remains UP
when the eth0 cable is unplugged?
Just a thought...
Cheers,
Jay
--
Jay Ridgley
jridgley2 at austin.rr.com
Registered Linux User ID - 9115
Registered Ubuntu User ID - 23320
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