Connecting to a VPN when using UFW https://askubuntu.com/questions/572497/cant-connect-to-pptp-vpn-with-ufw-enabled-on-ubuntu-14-04-with-kernel-3-18 sudo ufw allow proto gre from 86.121.33.88 You might also need to put into /etc/modules-load.d/pptp.conf: nf_conntrack_proto_gre nf_conntrack_pptp