Re: Enterprise Analysis DSTM Issue

[Suresh Satapati <satapati@gmail.com>]

On 8/10/05, Stig Venaas <Stig.Venaas@uninett.no> wrote:
> On Wed, Aug 10, 2005 at 06:31:45PM +0300, Pekka Savola wrote:
> [...]
> > On Wed, 10 Aug 2005, Tim Chown wrote:
> > >We can state in the analysis that we need
> > >a protocol for that scenario (#3 of RFC4057) that supports:
> > >
> > > a) v4-in-v6 tunnels
> > > b) automatic set up of v4-in-v6 tunnels when the host
> > >    doesn't have v4 address and an app wants to create a v4 socket
> > > c) authentication for tunnel setup
> >
> > OK, this is good.  Let's try to separate b) into three:
> >
> >   b1) automatic set up of v4-in-v6 tunnels
> >
> >   b2) automatic set up of v4-in-v6 tunnels when the host
> >      doesn't have v4 address
> >
> >   b3) automatic set up of v4-in-v6 tunnels when the host
> >      doesn't have v4 address and an app wants to create a v4 socket
> >
> > What are the requirements, exactly?
> 
> If you have sufficient amount of IPv4 addresses you could probably
> use several mechanisms where you set up tunnels and assign addresses
> to every client in the network. As I understand it, DSTM is in
> particularly useful when you have hosts that rarely need IPv4
> communications, you have enough IPv4 addresses to serve the hosts
> using IPv4 at any given time, but not for all the IPv4-capable
> hosts simultaneously. Hence the idea of being triggered by apps
> trying to use IPv4 (e.g. creation of v4 socket).
> 
> I'm not sure b2 makes sense above. You could automatic setup
> v4-in-v6 tunnel when hosts boots provided you have enough IPv4
> addresses. However, I think IPv6-only core only makes sense if
> IPv4 is rarely used. In that case it makes sense to have tunneling
> state only when needed. And as I said above, this may also make
> sense if you have lack of addresses. So the tunnel setup and the
> assignment of IPv4 address should only be done when needed. One
> way of detecting need, is request an IPv4 socket.

Not being judgemental about DSTM, one could argue such a method
of detection is outside the scope of this wg, or maybe even outside the
scope of IETF. 

> 
> I think several networks could manage with little IPv4 traffic
> already today. In particular if you have dual-stack mailservers,
> dual-stack web proxies etc. You would only need IPv4 to the
> internet when using more rare applications.
> 
> There are also some networks today that struggle getting enough
> IPv4 addresses for the network infrastructure...
> 
> Stig
> 
>