Significant Dropped Packets on WG interface

[Roman Mamedov]

On Thu, 14 May 2020 16:35:30 +0930
Mike O'Connor <mike at pineview.net> wrote:

> Hi All
> 
> For the last few weeks my Wireguard link which I use to as my default
> gateway has been having issues with TCP connections stalling.
> 
> I've been trying to work out what is wrong. I just noticed that the
> Wireguard link has dropped packets at both ends.
> 
> wg-p2p    Link encap:UNSPEC  HWaddr
> 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
>           inet addr:104.127.123.10  P-t-P:103.127.123.10 
> Mask:255.255.255.248
>           inet6 addr: 2506:c500:ff4:1::ab/64 Scope:Global
>           inet6 addr: fe80::e6/64 Scope:Link
>           UP POINTOPOINT RUNNING NOARP  MTU:1500  Metric:1

Reduce MTU of the WG interfaces to accomodate for overhead. See 
https://www.mail-archive.com/wireguard@lists.zx2c4.com/msg01856.html for
calculations of by how much.

>           inet6 addr: 2506:c500:ff4:1::aa/64 Scope:Global

I wonder what's this IP range, is this some VPN service? Squatting on
unassigned IPs within 2000::/3 seems like a very bad practice. If they wanted
an imaginary GUA for their NAT66, I'd suggest something like 66::/16 instead.

-- 
With respect,
Roman