Re: [Bitcoin-development] Bitcoind-in-background mode for SPV wallets

[Laszlo Hanyecz <laszlo@heliacal.net>]

On Apr 9, 2014, at 8:12 PM, slush <slush@centrum.cz> wrote:

> 
> These days IPv6 is slowly deploying to server environments, but maybe there's some simple way how to bundle ipv6 tunnelling into bitcoind so any instance will become ipv6-reachable automatically?
> 

Teredo is available by default on Microsoft systems and it's actually very common to see Teredo addresses as peers in torrents - this should work for bitcoin too, though I'm not sure if an app needs to set special flags to gain access to it.. there are probably some security settings around it.  In the US, AT&T/CenturyLink provide IPv6 by way of 6RD for DSL customers, Comcast has native IPv6 on residential (but not business) cable modems, and of course those who want to can always set up with a tunnel broker like Hurricane Electric - they even let you use your own IPv6 addresses.  IPv6 is great, but having an application running its own tunnels would not be a good way to leverage it.

Probably what's keeping a lot of them from being reachable is that most people just plug their CPE into a NAT router (without IPv6).  Teredo can help here though.
Putting an IPv6 checkbox in the settings with a link to an explanation might help with education and result in smarter operators who can make their nodes reachable.  A built in checker would be even better - something like a checklist showing red/green for different aspects of reachability (v4/teredo/v6).

-Laszlo