Question How to redirect an open port from an x app to another port ?

[AKHato]

So I play games , rockstar games rdr2 online, and the game asks me to open port 6672, but the thing is my router doesn't have a port forward option / DMZ at all,
and I cant connect to rockstar without using VPN, and if I'm not using VPN I must restart and wait my router / gpon to change to the ip that weren't blocking rockstar and that took some time.

So i use the VPN to connect to the game, i use mullvad.net for my VPN , so on mullvad i opened port 5856X.

The port on mullvad were random, when I make it it just gave me the number directly, with no choice of self input .
https://mullvad.net/en/help/port-forwarding-and-mullvad/

So how to redirect that 6672 on the game to the port that was assigned to me on the mullvad VPN ?

Thank You !

 

[bill001g]

It is somewhat surprising that the vpn service even offers the ability to in effect reserve a port to yourself. I assume you tried the obvious and tell the vpn server to open port 6672 directly.

I suspect they would not allow that port because someone else also using the same vpn server already has it or they just do not let anyone use the more common port numbers.

There are 2 different ip and port numbers.

You have external ip, external port
internal ip,internal port.

If it is the internal one can you change the server you are running to listen on a different port number. If not maybe there is a software app that you could load that would intercept the traffic and change the port. You can do this under linux pretty easy with iptables, then again iptables is messy. On windows I don't know.

If you are talking the external port I am somewhat surprised you can reserve a port in the first place. It would have to be a function of the vpn service to somehow let you use port 6672.

As with many of these projects when you start spending money for things like vpn etc to host servers many times you are just better off spending your money on rental from one of the server hosting companies. It just works and you save yourself all the hassel and depending on what the game is may not be a lot more expensive than the vpn service.

 

[AKHato]

It is somewhat surprising that the vpn service even offers the ability to in effect reserve a port to yourself. I assume you tried the obvious and tell the vpn server to open port 6672 directly.

I suspect they would not allow that port because someone else also using the same vpn server already has it or they just do not let anyone use the more common port numbers.

There are 2 different ip and port numbers.

You have external ip, external port
internal ip,internal port.

If it is the internal one can you change the server you are running to listen on a different port number. If not maybe there is a software app that you could load that would intercept the traffic and change the port. You can do this under linux pretty easy with iptables, then again iptables is messy. On windows I don't know.

If you are talking the external port I am somewhat surprised you can reserve a port in the first place. It would have to be a function of the vpn service to somehow let you use port 6672.

As with many of these projects when you start spending money for things like vpn etc to host servers many times you are just better off spending your money on rental from one of the server hosting companies. It just works and you save yourself all the hassel and depending on what the game is may not be a lot more expensive than the vpn service.

Question updated ~
Oh yeah , nah I haven't try to ask them directly , I just use their on the web form , and they just assign that port number to me , so I must dig about iptable equivalent on windows right, also thanks for the advice at the end of the post ^^.

 

[bill001g]

Why don't you just change change the port on the application in your pc to use the one you were assigned that way everything its the same

People connecting to you MUST use the port number you were assigned to contact your server even if you were to translate it inside your pc to something else. The port number that is assigned to you by the vpn service is the one that everyone else thinks is your actual port number. If the application on their machines does not allow them to change the port that is being used to the special one you were assigned you will never get this to function. You can do nothing to change the port the vpn provider gave you and you must change it in the software on the clients trying to connect to you.

 

[AKHato]

Why don't you just change change the port on the application in your pc to use the one you were assigned that way everything its the same

People connecting to you MUST use the port number you were assigned to contact your server even if you were to translate it inside your pc to something else. The port number that is assigned to you by the vpn service is the one that everyone else thinks is your actual port number. If the application on their machines does not allow them to change the port that is being used to the special one you were assigned you will never get this to function. You can do nothing to change the port the vpn provider gave you and you must change it in the software on the clients trying to connect to you.

I don't think red dead 2 online port can be changed ....

 

[bill001g]

Then you are out of luck I suspect.

Your problem is you have 2 parts of the network. Lets say you have port 12345 assigned to you by vpn provider and the game want to use 5555.

user------12345---vpn----5555-----your server.

Your issue is somehow you must change the port number the remote "user" is using. If their game only supports 5555 and they can't change it then you need something else between the user and the vpn to do that.
So you would need

user--5555--something---12345---vpn-----5555----your server. Problem is the "something" is outside your house.


I can't see a way to fix this. I am very surprised that the ISP even gives you a port. For some application where you can change the port number it would be useful. You for example could setup a web server and put in the url http://1.2.3.4:5555/xxxxxxxxxxxxxxx

 

[AKHato]

Then you are out of luck I suspect.

Your problem is you have 2 parts of the network. Lets say you have port 12345 assigned to you by vpn provider and the game want to use 5555.

user------12345---vpn----5555-----your server.

Your issue is somehow you must change the port number the remote "user" is using. If their game only supports 5555 and they can't change it then you need something else between the user and the vpn to do that.
So you would need

user--5555--something---12345---vpn-----5555----your server. Problem is the "something" is outside your house.


I can't see a way to fix this. I am very surprised that the ISP even gives you a port. For some application where you can change the port number it would be useful. You for example could setup a web server and put in the url http://1.2.3.4:5555/xxxxxxxxxxxxxxx

How about this port proxying ?
Performing port-proxying and port-forwarding on Windows · Embrace The Red [EXTERNAL LINKS]

 

[bill001g]

Where do you think you an run that command.

It might work to change the port on your server but the problem is between the remote user and the VPN server. You would have to be able to run that command on the VPN server or maybe the remote users machine.

I mean if this is someone you know well you could likely build a vpn over that port and then run the game inside that vpn using all the default ports. Not sure if the game allows that though some require the game company itself to connect to the server also

 

[AKHato]

Where do you think you an run that command.

It might work to change the port on your server but the problem is between the remote user and the VPN server. You would have to be able to run that command on the VPN server or maybe the remote users machine.

I mean if this is someone you know well you could likely build a vpn over that port and then run the game inside that vpn using all the default ports. Not sure if the game allows that though some require the game company itself to connect to the server also

Thanks for the explanation! ,
L&A Please , I think I already understand enough from the answer provided.