Point-to-point using GRE over IPv6 -> not possible with a single /128 address on the server?

[Peter G.]

On 15/02/2019 17:49, Peter G. wrote:
> Now the GRE tunnel
> 
>> ifconfig gre6 create
>> ifconfig gre6 inet6 fc01:e::100 fc:02:e::200 tunnelfib 6
> #ifconfig: ioctl (SIOCAIFADDR): File exists
> 
> Why is this not possible? Isn't the logic behind it the same as with
> IPv4? If not, why not?
> 
> Does this mean it is not possible to have a point-to-point using IPv6 on
> a machine with only a single /128 address?

Is this a stupid question, or something of the sort? Because I truly
don't understand why this wouldn't work. Thanks.

PG