Hi, On Sat, Sep 08, 2012 at 11:43:11PM +0200, Philipp Kern wrote: > Probably not RFC1918 addresses, but CGN ranges. And it's probably DNS64 which > breaks "stuff", rather than NAT64. There's also an effort in the IETF to spec > out 464XLAT, which will help the remaining cases of old software / network > stacks. NAT64 without DNS64 is of no real use - so yes - i meant DNS64 - It breaks at least DNSSEC and still NAT64 will most likely not work for all the little interesting protocols like SIP, FTP and the like because ALGs are to expensive for the vendors. On the other hand CGN (with the 100.64.0.0/10 address space) will most likely also not support ALGs, but in NAT44 world we are dealing with this for years. > But as Bastian said, and which you ignored, there's DS-lite for tunneling of > IPv4 over IPv6 to the provider. Which is not exactly NAT44. Right - DS Light is tunneling - but the IPv4 depletion will not be solved by it. You simply change the endpoint of your v4 session. I have seen DS Light on Power-Point from big ISPs like DTAG and O2/Telefonica and i have seen it on PowerPoint from Vendors like Juniper, Cisco and Ericsson/Redback. Yet i fail to find a good explanation what DS Lite solves? What is the benefit to Dual Stack? The Big see it as the end-of-the-v4-to-v6-transition when only few users will need an v4 Address and we shift away from Dualstack to Pure v6. I have seen this happing on PP in 2014-2015. Nothing in real life so far. IMHO this is a distant future when i'll have my Grandchilden on my lap. One reason this might get interesting is Vendor Licensing or Linecard Codespace - A Dualstack session requires twice the amount of resources on the linecards so all vendors halved their max-subscriber count with Dualstack. If one shifts aways the CGN/DS Lite concentrator from the BRAS one could save resources. But its just a matter of shifting resources and money around. RFC1925 (6) It is easier to move a problem around than it is to solve it. 1) This is why i guess we'll see niche networks using NAT64 (e.g. Mobile Operators due to Licensing issues) or DS Light - but my guess is that the big traffic will stay with Dual Stack + CGN for ages. Flo 1) By the time subscribers get v6 by default we have BRASes with a multitude of memory than we have today so the reason will get void. -- Florian Lohoff f@zz.de
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