Re: IPv6 over an ipv4 tunnel

> On Apr 3, 2025, at 16:35, Jack Raats <mlist@jarasoft.net> wrote:
> 
> Hi,
> 
> I have two servers, both running FreeBSD 14.2
> 
> Server A has only one ipv4 address, no ipv6.
> 
> Server B has one ipv4 address and an ipv6 subnet.
> 
> Is it possible to give Server A an ipv6 address from server B ipv6 subnet and ipv6 connectivity and how?


You can set up an IPv4 point-to-point tunnel between them, and then have server B delegate a small section of its IPv6 subnet (or a single address I suppose) to the far side of that tunnel.  It might only require setting IPv6 addresses on the point-to-point tunnel itself, but I’m not certain.

It should be easy to search for “ipv6 in ipv4 tunnel freebsd” to find instructions.  I know I’ve done things like this, but don’t have an example to look at right now.  I had set up a “gif0” tunnel interface to an outside provider, back in the FreeBSD 10/11 days (or before).  I would expect the same on your Server A, but I’m not sure if the setup on Server B will be that simple or more complicated.

            - Chris