On Tue, 16 Apr 2013, Jerald A DeLong wrote:
Some networks don't speak IPv4 anymore.
This will have to be addressed in *NOS in time (or abandonment).
Dual stacked nodes are going to be in use for some time ipv4 isn't going to get shut off tomorrow.
This year some residential access networks will shut off IPv4 in a way that prevents running an amprnet gateway over IPIP or IPUDP tunneling. Operators are putting IPv4 more and more behind "carrier-grade NAT" devices, and not giving any public IPv4 addresses to the customers at all. The NAT is being done on the operator's device, so plain IPIP or IPUDP tunneling as we do it now won't work at all.
At the same time, some of them are starting to give public, routable IPv6 addresses to the end customer. If you use IPv6 for your connection, you bypass the NAT! You could do IPv4 over IPv6 tunneling to get your AMPRnet, for example, but since not all gateways have IPv6, you couldn't have a full mesh of connections to all other gateways. There could be a set of IPv4+IPv6 enabled gateways which would relay traffic for you from IPv4-only gateways. Or something like that.
For example, see DS-Lite:
http://en.wikipedia.org/wiki/IPv6_transition_mechanisms#Dual-Stack_Lite_.28D...
Not all network operators will be doing this, but some. At work we talk with operators a lot, since we make software for them to sell and deliver to their end customers. We're getting questions about IPv6 deployment and operators are checking with us how our software will work when they deploy.
- Hessu, OH7LZB