Update: Sorry guys, looks like I just needed to reboot the public server.

My goal is to forward port 8096 from my private server to my public server. That, is any traffic at public server’s port 8096 should be tunneled to port 8096 of my private server and back.

I’ve set up a wireguard tunnel and ping is working from one device to the other. In this, 10.8.0.1 is the private server and 10.8.0.2 is the public server.

Here are my config files (/etc/wireguard/wg0).

--- On the public server ---
[Interface]
Address = 10.8.0.2/24
ListenPort = 51820
PrivateKey = *****************************************

# packet forwarding
PreUp = sysctl -w net.ipv4.ip_forward=1

# port forwarding
PreUp = firewall-cmd --zone=public --add-port 8096/tcp
PreUp = iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 8096 -j DNAT --to-destination 10.8.0.1:8096
PostDown = iptables -t nat -D PREROUTING -i eth0 -p tcp --dport 8096 -j DNAT --to-destination 10.8.0.1:8096
PostDown = firewall-cmd --zone=public --remove-port 8096/tcp

# packet masquerading
PreUp = iptables -t nat -A POSTROUTING -o wg0 -j MASQUERADE
PostDown = iptables -t nat -D POSTROUTING -o wg0 -j MASQUERADE

[Peer]
PublicKey = *****************************************
AllowedIPs = 10.8.0.1

--- On the private server ---
[Interface]
Address = 10.8.0.1/24
PrivateKey = *****************************************

[Peer]
PublicKey = *****************************************
AllowedIPs = 10.8.0.2
Endpoint = <public-server-addr>:51820
PersistentKeepalive = 25

Now, I’m trying to test the connection using netcat. I’m listening from my private server using nc -l 8096 (I’ve made sure that the port is unblocked) and trying to connect from a third device using nc <public-server-addr> 8096 but it’s not working.

I have no idea what’s going on here. Some help from experienced people is very appreciated.

  • EskueroAEnglish
    2·
    1 year ago

    It’s been a long time since I did forwarding through wireguard so this might be outdated, missing info or actually doing unneeded stuff but I had this notes saved in some old iptables personal documentation from like 4 years ago that might shed you some light:

    Allow first packet to start the connection

    iptables -A FORWARD -i eth0 -o wg0 -p tcp --syn --dport 80 -m conntrack --ctstate NEW -j ACCEPT
iptables -A FORWARD -i eth0 -o wg0 -p tcp --syn --dport 443 -m conntrack --ctstate NEW -j ACCEPT

    Allow already established connections

    iptables -A FORWARD -i eth0 -o wg0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i wg0 -o eth0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT

    Send whatever arrives via port 80 or 443 to the other side of the wg tunnel

    iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j DNAT --to-destination 192.168.3.1
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 443 -j DNAT --to-destination 192.168.3.1

    Modify source address so it can return

    iptables -t nat -A POSTROUTING -o wg0 -p tcp --dport 80 -d 192.168.3.1 -j SNAT --to-source 192.168.3.2
iptables -t nat -A POSTROUTING -o wg0 -p tcp --dport 443 -d 192.168.3.1 -j SNAT --to-source 192.168.3.2