Disclaimer: this is a rather technical topic network related.
I’ve been using a netvm for a wireguard VPN for a while, it’s working fine, now I wanted to add a firewall qube between the qubes and the vpn qube, but this drastically reduce the available bandwidth over the VPN.
I have a slow ADSL connection with a maximum upload of 100 kB/s, when using the VPN directly, I can fill the download bandwidth without reaching my upload limit.
When adding a qube firewall, it almost double the bandwidth used for uploading packets (like if it added fragmentation maybe?) and so it reduces my download bandwidth as it’s capped by the upload…
Download speed over the VPN : solid 1 MB/s results in a physical interface upload of 43 kB/s
Download speed over the VPN with extra firewall : barely 1 MB/s results in a physical interface upload of 100 kB/s
Not sure if it’s clear?