Re: IPv4 Address Flags

[David Laight <david%l8s.co.uk@localhost>]

On Tue, Apr 21, 2015 at 05:48:46PM -0700, Dennis Ferguson wrote:
> 
> On 21 Apr, 2015, at 01:46 , Roy Marples <roy%marples.name@localhost> wrote:
> > As discussed here [1], a few people voiced their opinion that they
> > didn't like address removal when the carrier drops and would rather
> > re-negotiate at carrier up. The first step of doing this is to add IPv6
> > address flag semantics to IPv4 addresses.

Dropping ip addresses and connections on 'carrier down' seems pointless
to me.
You can't detect the cable being unplugged 'one switch back', so
why do you care about the local cable being unplugged.
All it does is give people an incorrect view of how fast TCP will
detect neteork outages.
 
> To tell the truth I think this is fixing the problem in the wrong
> spot.  I don't see a big difference between unplugging the ethernet
> cable and plugging it back in, and unplugging the USB or Thunderbolt
> ethernet dongle and plugging it back in, or hot-swapping the ethernet
> line card out and replacing it with another.  If I have active protocol
> connections I would like them to survive the interface itself going
> away and coming back just as much as I would like them to survive
> the special case of the carrier dropping and coming back.  Adding
> complexity to deal only with the latter doesn't seem worth it.
...

On linux we've had to use a 'bond' of one interface in order to stop
USB interface interface disappearing due to electrical transients.


	David

-- 
David Laight: david%l8s.co.uk@localhost