How to specify port when entering destination ip?

[GC2023]

I am trying to a Firewall rule for inbound services on port: 4 so that they are redirected to my raspberryPi flask web server on 192.168.0.17:5000. 5000 being the port of the raspberry pi where the web server is. The problem is that when trying to specify port: 5000 is the destination ip it will not allow more than three characters in the box two of which is 17 and then the : so I don't have space to enter the port number. Here is a screenshot:

The last box of the destination ip can only take three numbers. Is there a work around?

[TimmyBGood]

@GC2023 

I would assume that means you're trying to enter the information in the wrong place, and that box can only contain an IP address without a port number.

[Chrisee]

@GC2023 there are two stages to the process so what ports have you defined as the Rapberry Pie rule? See https://helpforum.sky.com/t5/Broadband-Talk/How-to-set-up-port-forwarding/ba-p/2662260 I am not aware that you need to define a destination port on a device as surely the webserver itself is listening for traffic? 

One point to remember is that you will need to set-up a dynamic DNS account with a supported provider if you intend to run an externally accessible server on a Sky connection as your public IP address changes periodically unless you have a legacy fixed IP address which are very rare these days.

[jamesn123]

@GC2023 

Port mapping isnt possible on the Sky router you cant go from port 4 to 5000. It has to be a 1 to 1 mapping e.g. 25 to 25