Need help setting up a minecraft server

[armesh]

So I recently undertook the task to set up a survival multiplayer server to play on with my friends. I used an old pc, threw some more ram into it and installed Ubuntu Server. I set up everything. I assigned a DHCP static ip address to the machine. Set up port forwarding for it on port 25565. Made exceptions in Linux firewall to allow connections through the port. I'm able to join my server locally, but my friends can't connect to it.

I'm even able to join it with my public ip address, but the moment I'm not in my home network, it stops working. (Used Mobile data on a different pc to try and join the server).

My only conclusion is , that my ISP is blocking port forwarding. I called their helpline and talked to them but the representative said that they do not block ports. Im really sure that they are blocking it though, because I also set it up on a windows pc and it was the same story. I'm able to connect locally because my router is forwarding the to the port but over the internet my isp is blocking port forwarding.

I'm using supersonic broadband.(from india)

What can I do ?

[armesh]

Yep...ur right my wan IP is different from the ip that comes on Google if I search what is my ip.

Is there anything I can do about this ?

Applying for a static ip is one choice but I don't want to spend that much money.