found my notes. I have to use this command:
-
sudo ip link set dev eth0 mtu 1380 -
has to be set in
/rw/config/rc/local
But I’m not sure that’s entirely correct. I remember that counterintuitive thing (for me, anyway), was about which VM I set it in. So consider:
When I check my proxyVM /rw/config/rc/local, it has the this:
#!/bin/sh
# This script will be executed at every VM startup, you can place your own
# custom commands here. This includes overriding some configuration in /etc,
# starting services etc.
# Example for overriding the whole CUPS configuration:
# rm -rf /etc/cups
# ln -s /rw/config/cups /etc/cups
# systemctl --no-block restart cups
wg-quick up /home/user/[YOUR MULLVAD WG SERVER].conf
# https://forum.qubes-os.org/t/mullvad-proxy-vms-suddenly-stop-working-except-for-mozilla-org-redcross-org-and-wikipedia-org/18668/14
iptables -t nat -I POSTROUTING 3 -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
But in my AppVM /rw/config/rc/local, it has this:
#!/bin/sh
# This script will be executed at every VM startup, you can place your own
# custom commands here. This includes overriding some configuration in /etc,
# starting services etc.
# Example for overriding the whole CUPS configuration:
# rm -rf /etc/cups
# ln -s /rw/config/cups /etc/cups
# systemctl --no-block restart cups
# Set MTU to 1380 to work with Mullvad VPN
sudo ip link set eth0 mtu 1380
So it looks like you have to set the MTU in the AppVM.
It took me a while to figure that out - particularly working out exactly what MTU value to use, YMMV - hope it saves you some time. (But as I say, my computer knowledge is limited).