I've got a debian server at home, that I use to have a VPN access to my home computers.I've redirected the openvpn port on the port 2000 : in my file server.conf, I've added this :#Server mode server proto udp port 2000With the connexion tracking, I allow all the related and response connexions.I've set up a rule, allowing everybody on the port 2000 :iptables -t filter -A INPUT -p tcp --dport 2000 -j ACCEPThowever, it doesn't allow me to connect to my VPN (if I disable the firewall, I can connect without any problem).So, what haven't I understood? does openvpn need another port?
netfilter's configuration to allow openvpn
iptables;openvpn
You need to modify your iptables rule: It should be for UDP, not for TCP. Additionally, your server gets the UDP traffic to port 2000 as your router rewrites the destination port and IP:      iptables -t filter -A INPUT -p udp --dport 2000 -j ACCEPT