Date: Fri, 4 May 2001 16:07:24 +1000 (EST)
From: Roger Venning <c729953@vus068.trl.telstra.com.au>
To: "David S. Miller" <davem@redhat.com>
cc: Janice Girouard <girouard@us.ibm.com>, netdev@oss.sgi.com
Subject: Re: NETDEV_CHANGE events when __LINK_STATE_NOCARRIER is modified
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On Thu, 3 May 2001, David S. Miller wrote:

> 
<snip> 
> It is not a physical state change.  This state bit is meant only as a
> hack for the isdn layers dial on demand like functionality.
> 
> This is not the kind of state change the notifier chain listeners are
> interested in.  It would be meaningless for the notifiers to run
> every time I yank my ethernet cable out of the card on my machine :-)

(presuming first that these events can be propagated up to user space
through some kind of listen on a socket style API, something that I don't
think is possible _yet_)

I beg to differ a little. Considering the case with the machine has
multiple network interfaces, and a mobile IP (RFC2002 and 
friends) capability, this kind of notification is crucial to smoothly
transferring traffic onto other available interfaces (think mobile pda
with ethernet & wide area cellular data). This is just one instance of
'middleware' style applications that would prefer not to poll this kind of
state.

Roger.

> 
> Later,
> David S. Miller
> davem@redhat.com
> 

--
Roger Venning - Technologist - Telstra Research Laboratories

          For a successful technology, reality must take
          precedence over public relations, for Nature
          cannot be fooled.                 Richard Feynman