Re: Allowed IPs Toggling

[Samuel Holland <samuel@sholland.org>]

Hello,

On 03/15/18 10:31, Gianluca Gabrielli wrote:
> I was setting two peers on the server, but every time I re-add one of these 
> two the other one is shown with (none) on "allowed ips" field. Of course that
> blocks communications with that peer. If I try to re-add it, then the other
> peer loses its configuration, same problem.

Allowed IPs is like a routing table; you can't have two routes for the same set
of IPs, or WireGuard doesn't know which peer to send the traffic to. You want to
have non-overlapping Allowed IP ranges. This usually means that the range of
Allowed IPs is smaller than the host's subnet. For example:

Host A:
IP configuration for WireGuard interface: 192.168.123.1/24
Allowed IPs for Host B: 192.168.123.2/32

Host B:
IP configuration for WireGuard interface: 192.168.123.2/24
Allowed IPs for Host A: 192.168.123.1/32

The IP configuration tells the kernel which IP ranges are accessible via the
WireGuard interface. The Allowed IPs tell WireGuard, which _subset_ of those IPs
is associated with each peer.

> Cheers,
> Gianluca

Cheers,
Samuel