Enabling firewall creates a lot of iptables rules. As a result, the default settings block pptp traffic.
How to disable unnecessary rules that proxmox creates a default?
hmm i tried with proxmox 4 last year, but i got an module error on startup.
i only have to fill in this 3 words?
modprobe ip_nat_pptp
modprobe ip_conntrack_pptp
modprobe ip_gre