enabling WG0 allows telegram but impedes browsing

[Roman Mamedov]

On Fri, 20 Aug 2021 13:16:34 +0200
S Bauer <sanderbauer at gmail.com> wrote:

> Hello team,
> 
> Hoping you could help me out with a foggy situation.
> The past week I have been struggling to get the Wireguard VPN working
> smoothly. Everything seems to work on paper, except in a specific way
> it doesn't. I am using Pop!_OS 21.04 (Ubuntu Hirsute).
> 
> SitRep;
> I work as a freelance consultant and want to be careful about the
> local networks' peeping tom when accessing sensitive work documents
> from 'out of office', e.g. at a friend's place or at a hotel. So my
> objective is to access my home network via PiHole and then continue
> onward to access my work-related documents on a fileserver.
> I was hoping this could be easily achieved with Wireguard.
> 
> Using the Wireguard VPN wg0 with wg-quick worked perfectly when I
> connected to my brother's phone hotspot (4G). I could access our home
> via VPN as expected and could work on my documents without any
> problems.
> The trouble is that I am now at a different location, working with a
> fixed router from Ziggo NL. For some reason the WG0 still connects
> perfectly, but after that a small mystery occurs. I did not make any
> modifications to WG0.conf, so I remain stumped.
> With WG active, I am no longer able to access any webpage. So no
> access to protonmail\gmail, reddit or anything else. Telegram,
> however, is still working fine. Internal machines on the home's local
> network (IP-camera) can also be accessed directly.
> Disabling the WG gives me full access to any webpage as usual. So
> something is amiss that affects my browser only (Firefox 91.0).

What's your MTU on the wg0 interface? Try reducing that to 1400, or if
that doesn't help, to 1280.

-- 
With respect,
Roman