[6bone] Re: IPv6-only IXP's are absolutely wrong

[Eric Gauthier]

> On Sun, Oct 20, 2002 at 05:13:47PM -0700, Bill Manning wrote:
> > 	it is true that for L2 fabric, it can be hard to prevent IPv6 or IPv4
> > 	from using the fabric.  There are reasons to try and split them however.
> > 	This is not the right thread to take on that topic though.
> > 	If this is of interest, send a note and I'll forward on the rational.
> 
> I'd like to hear more about that.  At the german DE-CIX, we do v6 and v4
> on the same mesh, just to make it easy to get v6 native peerings deployed,
> and of course I'd like to hear all possible "why" and "why not"'s...

I don't know about the various IX's, but the I2 gigapop that our University
uses is concerned about this.  If I remember correctly (not that the exact 
numbers are important), but IPv4 is in an ethernet frame with type 0x0800 and 
IPv6 is in an ethernet frame with type 0x86dd, so layer 3/4 aware switches 
will likely handle these frames differently.  In our case, the Cisco 12,000 
and 6500's that we're using are great for IPv4 packets (they handle them
in hardware), but IPv6 packets are handled in software so we don't expect 
nearly the same type of performance.  I'd imagine that something like this 
is what they're alluding to.  

Eric :)