How to enable ipv6 tunnel?

You can use Mirebo: http://www.remlab.net/miredo/

You can find it as server or client package http://packages.ubuntu.com/search?searchon=names&keywords=miredo

Good luck.

Thanks Cristi Nistor, that solved my question.

Could it be set up to try IPv4 route first? Looks like miredo hijacking it and crawls to nearby machines via tunnel broker.

It's up to each and every application to follow the address selection policy.
By default, public IPv4 is preferred over Teredo anyway.

This is not a miredo issue. If you want to change the policy, edit /etc/gai.conf, which is part of glibc.

IPv4 is preferred for most of the applications that you will find accessing the
internet. So its a good practice to use that so you don't run into conflicting
applications.

--
Regards,
Vikram Dhillon

On Tuesday 24 November 2009 08:43:29 am Rémi Denis-Courmont wrote:
> Question #91497 on miredo in ubuntu changed:
> https://answers.launchpad.net/ubuntu/+source/miredo/+question/91497
>
> Status: Open => Answered
>
> Rémi Denis-Courmont proposed the following answer:
> It's up to each and every application to follow the address selection
> policy. By default, public IPv4 is preferred over Teredo anyway.
>
> This is not a miredo issue. If you want to change the policy, edit
> /etc/gai.conf, which is part of glibc.
>

> By default, public IPv4 is preferred over Teredo anyway.
So, it looks like defaults are broken. Firefox and ssh definitely preferring v6 over v4.

First, I would like to emphasizes that GNU/libc will prefer *public* IPv4 addresses over Teredo IPv6 source addresses. But it will prefer Teredo addresses over *private* IPv4 addresses. This is consistent with the specification (IETF RFC3484).

So if you are behind a NAT (which is likely the case if you are using Teredo), Teredo is favored over IPv4. This is expected glibc behaviour. And in fact, it turns out that _this_ specifically is not configurable, not even through /etc/gai.conf contrary to my earlier implication.

In any case, this is not something that miredo can do anything about. If you don't want to use IPv6, then don't use miredo, or tspc, or 6to4 or any IPv6 mechanism. The policy is obtained via getaddrinfo() which is part of GNU/libc, and only a change to the libc6 package can affect this.

> IPv4 is preferred for most of the applications that you will find accessing the
> internet. So its a good practice to use that so you don't run into conflicting
> applications.

This is totally untrue. Any application using getaddrinfo() will prefer IPv6 over IPv4 in most cases - if both IPv4 and IPv6 are available on the local and remote system, that is.