ifdown. is it really down?

[Bruno Wolff III]

On Mon, Jun 30, 2008 at 22:47:54 +0000,
  g <geleem at bellsouth.net> wrote:
> Bruno Wolff III wrote:
>> I don't believe that it is normal to power down the device when ifdown is
>> run. So the device will still flash is traffic is sent to it.
>
> i do not 'power down'. i just use 'ifdown eth0' in a script.

I think you misunderstood. I was suggesting that normally ifdown won't turn
a device off, so it will still see ethernet traffic sent to it.

> also, now thinking about mentioning it, when i bring up thunderbird, there are
> double flashes, 3 to 4 more doubles, sometimes 5 of ethernet led on 2wire.

This makes it sound like the interface is still active. You can use the ip
command to get more information about your network devices. ip link will
show you the status of each link and ip addr will show you the addresses
bound to each link. That might help diagnose what's going on.