Re: address pair exploration, flooding and state loss

[marcelo bagnulo braun <marcelo@it.uc3m.es>]

Hi Iljitsch,


El 01/06/2005, a las 12:31, Iljitsch van Beijnum escribió:

> On 31-mei-2005, at 23:03, Erik Nordmark wrote:
>
> > > Another way to do this would be the "ICMP bad  checksum" message 
> > > that I suggested a few days ago.

would this be a mandatory change (i.e. required to make the SHIm work) 
or just an optimization?

I mean, i don't think that it would be a good idea to require mandatory 
changes on transport layers, even if they only involve TCP, UDP and 
SCTP...

Regards, marcelo


> > But as I responded, such an approach only makes sense if we are going 
> > to modify all the protocols which run over IP to generate such 
> > errors. And assuming that an implementation can do this is 
> > problematic due to "raw socket" APIs which allow there to be any 
> > number of IP protocols implemented unbeknown to the provider of the 
> > IP and shim6 layers.
>
> AFAIK, applications that use raw sockets for actual user traffic are 
> extremely rare. (I can't think of any, not counting IP tunnels.) 
> Typically, applications use UDP for "strange" protocols. So if we 
> modify TCP, UDP and SCTP we should be out of the woods here. And if 
> there really are applications that don't use these transports but are 
> interested in recovering quickly from shim state loss, it shouldn't be 
> too hard for them to implement the "icmp bad transport checksum".