"RoS discovered a number of new findings, and we would like to thank them for their thorough and detailed report. They stated , amongst other things that: that whilst they found some issues, that: “The Mullvad VPN relays which were the subject of this test showed a mature architecture…” and “During the test we found no logging of user activity data…”
I appreciate the breakdown, but I meant i was ignorant on why port forwarding was important for a VPN :) Was still a great write up that should be used as reference for others! :D
I didnt realize you still had to port forward to get around ISP traffick shaping/blockage with a VPN. Thought the encrypted tunnel between you and the VPN disguised that, and any port stuff was done at their end, after exiting the tunnel.
If the VPN doesn’t use port forwarding, then they randomly assign a port. But P2P services expect to know which port they need to use, so getting a port assigned randomly is no good for said P2P services. You want a static port that is forwarded by the VPN that you can tell the P2P service.
So if you’re not using a P2P service that needs a port to access, then a non-port-forwarding VPN will still do all the usual encryption to disguise your activity as usual. But if you are using a P2P that needs to access a specific port, the P2P service will probably get blocked at the VPN’s port.
@Helldiver_M @Dubious_Fart @leraje actually the port forwarding thing is about accepting inbound connections. Without port forwarding, NAT routers (including VPNs) randomly allocate ports for outbound connections but still won’t accept inbound connections on those same ports.
There’s a trick where you discover the randomly allocated port numbers and then both connect to each other at the same time so both routers think it’s outbound. It works unreliably and BitTorrent doesn’t use it.