Mullvad
That’s it. We are officially out of ports. We knew this day would come; that 16 bits of memory in the TCP packet simply wouldn’t be enough to provide port forwarding for everyone.
That’s why, from now on, it will no longer be possible to request a port that will forward inbound traffic through whichever server you are connected to. However, we didn’t want to abandon this feature entirely, so we came up with a compromise: Allocate ports on a per-city basis. This means that in order to request a port, you have to select a city and as long as you are connected to a server within that city, inbound traffic to that port will be forwarded as usual.
If you currently have port forwarding set up with “global” ports assigned to your account, they will keep working on all servers for the time being. They will eventually have to be reclaimed however and we will give you a heads up before that happens but to guarantee a stable service, we recommend that you replace your current ports with city-specific ports at earliest convenience.