However my VPN provider does not give my client machines public IPs and instead gives them internal IPs.
So from any machine in my home, my normal (via ISP) connection is via my own router (which does NAT for all machines in my home network and which I fully control) which has a public IP address on its external interface (so, no double NAT), whilst a VPN connection is via the VPN provider’s router (as that’s what’s on the other end of the VPN pipe) which also does NAT, but that router I don’t control and the VPN provider I use doesn’t allow Port Forwarding hence all the trickery I described above to make sure I actually seed more than I download.
Around here ISPs giving internal addresses is not very common unless it’s on a mobile connection.
Does your ISP not give your router a public (even if dynamic) IP? If not, then after your router you’d be double-natted right? Yuck!
My ISP does give my router a public IP.
However my VPN provider does not give my client machines public IPs and instead gives them internal IPs.
So from any machine in my home, my normal (via ISP) connection is via my own router (which does NAT for all machines in my home network and which I fully control) which has a public IP address on its external interface (so, no double NAT), whilst a VPN connection is via the VPN provider’s router (as that’s what’s on the other end of the VPN pipe) which also does NAT, but that router I don’t control and the VPN provider I use doesn’t allow Port Forwarding hence all the trickery I described above to make sure I actually seed more than I download.
Around here ISPs giving internal addresses is not very common unless it’s on a mobile connection.