Router Configuration for Painkiller Multiplayer Server

Routers vary in configuration so I'll describe the router configuration on my TP-Link router.

Basically, you need to allow the incoming connection from a client to your server on an indicated port. The default port for the original Painkiller is 3455 and for Painkiller Overdose it is 4974. However, you can change a port in the game.

Home routers do not usually block any outgoing traffic but firewalls can so you may need to create the firewall inbound and outbound rules for the game via TCP and UDP protocols. Inbound rules are required so that the client can connect to your server while outbound rules are required for the Painkiller game to advertise its server to openspy.net master servers and send packets to the client properly. From my experience, I did not have to configure the OS firewall at all.

The scheme shows how the traffic flows from a client to a server.

flowchart BT
  A{{Client}} -->|50.153.139.143:3455| B[Router External IP];
  B -->|192.168.0.104:3455| C[OS Firewall];
  C -->|TCP, UDP| D{{Server Internal IP}};
  D --> E[OS Firewall];
  E -->|TCP, UDP| F[Router External IP];
  F -.-> A;
  F -.-> J([openspy.net]);
  J -.-> A;

From the scheme above let's assume that 50.153.139.143 is your external IP address, 3455 is the default Painkiller port, 192.168.0.104 is the IP address of your local server.

Configuration

In the following instruction, we will reserve the internal IP address and forward a Painkiller/Overdose port to it.

Open Windows CMD/Powershell or Linux Terminal and type in the hostname command to find out your PC name. Alternatively for Windows, the hostname can be checked in the Windows System properties.
Access your router. In my case, it is http://192.168.0.1/ via a web browser. It may vary depending on your router model.
Click DHCP -> DHCP Clients and locate your PC hostname. You'll see something like this:

ID Client name Mac address Assigned IP address Address lease time

1 MyPC 09-9A-D9-48-6C-DC 192.168.0.104 01:21:48

Note

You may have a different assigned IP address and the Mac address.
Go to DHCP -> IP reservations, click Add and assign an IP address to the Mac address of your PC:

ID Mac address Reserved IP address Status

1 09-9A-D9-48-6C-DC 192.168.0.104 Enabled
Restart your router. Then if you go back to DHCP -> DHCP Clients, you'll see that the Address lease time is permanent for 192.168.0.104.

Now go to Port Forwarding -> Virtual servers -> Add and forward a port to the internal IP address of your PC server for TCP and UDP protocols:

ID	Service port	Internal port	IP address	Protocol	Status
1	3455	3455	192.168.0.104	TCP	Enabled
2	3455	3455	192.168.0.104	UDP	Enabled
3	4974	4974	192.168.0.104	TCP	Enabled
4	4974	4974	192.168.0.104	UDP	Enabled

Note

Some routers have the All option under Protocol that includes both TCP and UDP.

The default port for Painkiller is 3455 and for Painkiller Overdose it is 4974.

Check the connection. I will not go into the detail but the UDP connection can be checked with nc (change the IP address and the port accordingly):
```
nc -vz -u 50.153.139.143 3455
```
The result will look similar to this:
```
Connection to 50.153.139.143 3455 port [udp/*] succeeded!
```