[arin-ppml] IPv6 Non-connected networks

Roger Marquis marquis at roble.com
Thu Mar 25 01:21:41 EDT 2010

Lee Dilkie wrote:
> Is no one concerned that NAT breaks a lot of networking, especially
> peer-to-peer, and forces some really inefficient technologies, like
> SBC's, to exist?

Statements like this make me wonder if they don't teach the value of
field testing in networking curriculums.  Without field testing you
wouldn't know if the packet filtering that will be needed to replace the
privacy and security NAT provides are worse than NAT itself.  Field
testing would also show that consumers don't want to register their
internal IPs, don't want end-to-end transparency, and don't want to give
a free pass to badly designed protocols (like SIP) that they require deep
packet inspection to work well with NAT.

The need for deep inspection is what "breaks a lot of networking".  It is
a mistake to blame this on NAT.  Continuing to make this mistake, and
ignore the past few years field trails, or the overwhelming consumer
demand (for NAT), will only continue to limit the adoption of IPv6 to
those few sites who don't need NAT (mainly carriers).  Because of the
results of IPv6 field testing I'm willing to bet good money that NAT will
be around long after we are all gone, and future network engineers will
look back and wonder what those NAT-dissing engineers were smoking.
I obviously value field testing.

> There is a lot of network media traffic (example, VoIP) that is
> unnecessarily backhauled across the internet because of NAT and in an
> NAT-less IPv6 world could use less network resources and be more reliable.

I don't see that.  I see quite the opposite.  My own VOIP sites for
example, which work seamlessly with NAT.  It just works because the
firewalls do deep inspection where they have to (SIP) and we use well
designed protocols (IAX2) where we can.

Roger Marquis

More information about the ARIN-PPML mailing list