IPv4 address length technical design

Sun Oct 7 07:37:38 UTC 2012

On Oct 6, 2012, at 11:35 AM, Barry Shein <bzs at world.std.com> wrote:

> 
> We can map from host names to ip addresses to routing actions, right?
> 
> So clearly they're not unrelated or independent variables. There's a
> smooth function from hostname->ipaddr->routing.

No.

Not just no, but hell no at the asserted communativity there, Barry.

That's not even Wrong...

And that's the point.

DNS to IP is in no way a smooth function.  Hell no, for many networks.  It's only true for the boringest customers.  Try actual enterprise endpoints, or service providers.

IP to Routing is not smooth at predictable scales.  Yes, it's in blocks, but a top-down view is at best fractal discontinuity.

IP to routing is smoother in IPv6 but as routing has two components - physical location and net path - was made smoother in one only ( net path, and to the degree that's smooth in physical location by accident...).

George William Herbert
Sent from my iPhone