Yes, the internal IP is leaked. But, also the IP assigned to you by your ISP is leaked (just tested with http://net.ipcalf.com/ http://net.ipcalf.com/ & a vpn).

Yes, the internal IP is leaked. But, also the IP assigned to you by your ISP is leaked (just tested with http://net.ipcalf.com/ http://net.ipcalf.com/ & a vpn). Though, I did test this on a college campus, so the network might just be leaking my internal ip, which ends up being my external ip also because of how they have the network setup. Which in hindsight is actually even scarier.