Joe Abley wrote:
On 25 Feb 2005, at 20:39, Philip D'Ath wrote:
I'm talking about using NAT-PT to allow a native ipv6 network to talk to an ipv4 network. Without some kind of protocol translation (aka PT) ipv6 can't talk to ipv4. The reason this has to be done is because you can't buy an ipv6 connection to an ISP in NZ yet.
In the absense of local carriers with dual-stack edge routers (i.e. in the case of most of the planet) the way you do this is terminate a tunnel somewhere.
I humbly disagree. My experience with public end user tunnel brokers is that none of them are "close" enough to NZ. No matter who you broker with you end up paying in huge (>3000ms in some cases!) RTT's, this is especially true of the large US tunnel brokers such as hurricane electric and freenet. A much more reliable way (IMHO) to play with IPv6 in New Zealand is to use 6to4. 6to4 gives you a /48 to play with for every IPv4 address you have, so it's a viable to run in conjunction with, or even instead of, IPv4 NAPT. If you are stuck behind a NAT device that doesn't support 6to4, you can also probably use Teredo to similar advantage. Both Teredo and 6to4 are built in to XP SP2 for those of you still clinging to the dark side <grin>. There is also nothing stopping you combining these (6to4 and a tunnel to a couple of providers) as having multiple IP's per interface is not only supported by IPv6, but is required, and interfaces tend to end up collecting IPv6 addresses like a stamp collector collects stamps. One thing to be wary of is that inadequacies in the Linux implementation make this suboptimal (Linux chooses the most recently added IPv6 address on an interface as the source for outgoing connections, which of course is the tunnel with the highest setup time (and therefore highest RTT)). ISP's could help encourage IPv6 adoption in New Zealand without having to run v6 throughout their entire network by running Teredo and 6to4 anycast servers with peering (via tunnels if necessary) to places like APE6/WIX6, Aarnet, and other networks that are topologically close to the ISP. (For those interested in v6, but never had the time to experiment: * http://www.wlug.org.nz/Teredo * http://www.wlug.org.nz/6to4 * http://www.wlug.org.nz/IPv6 Also the WLUG site has a dancing penguin if you're using IPv6 instead of the static one in the normal logo as an easy way to test IPv6 within New Zealand.)