North American Network Operators Group

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Re: Access to the IPv4 net for IPv6-only systems, was: Re: WG Action: Conclusion of IP Version 6 (ipv6)

  • From: Iljitsch van Beijnum
  • Date: Tue Oct 02 08:14:54 2007

On 2-okt-2007, at 11:36, John Curran wrote:

The proxy&tunnel vs NAT-PT differences of opinion are entirely based
on deployment model... proxy has the same drawbacks as NAT-PT,

The main issue with a proxy is that it's TCP-only. The main issue with NAT-PT is that the applications don't know what going on. Rather different drawbacks, I'd say.

only without the attention to ALG's that NAT-PT will receive,

ALGs are not the solution. They turn the internet into a telco-like network where you only get to deploy new applications when the powers that be permit you to.

and tunnelling is still going to require NAT in the deployment mode once
IPv4 addresses are readily available.

Yes, but it's the IPv4 NAT we all know and love (to hate). So this means all the ALGs you can think of already exist and we get to leave that problem behind when we turn off IPv4. Also, not unimportant: it allows IPv4-only applications to work trivially. Another advantage is that hosts with different needs can get different classes of tunneled IPv4 connectivity even though they happen to live on the same subnet, something that's hard to do with native IPv4.