Browsers no longer leak local ip addresses, there's a new feature that uses mDNS instead of local ips.
Re:Why Is This Website Port Scanning Me?
by jimmaswell on Wednesday May 20, 2020 @11:05AM
(#23247718)
> Prevent WebRTC from leaking IP adresses
A local IP?
Re:Why Is This Website Port Scanning Me?
by Cactus2018 on Wednesday May 20, 2020 @11:48AM
(#23248284)
FYI about these two websites that demonstrate the various data your browser shares:
Yes, oddly enough. It can be used by a website you visit to gain information about your local network which turns out to be incredibly effective for fingerprinting.
WebRTC can also leak your IP when you're hiding behind a VPN.
Any way to stop that?
The best solution is running the VPN client in your router. That way, your machine can't see its ISP-assigned public IP address.
If you're using a workspace VM, you can run the VPN client in a pfSense VM, which is functionally equivalent.
If you're not using a workspace VM, and can't run the VPN client in a router, you can run the VPN client in a pfSense VM. You bridge the WAN interface of the pfSense VM to the host LAN adapter. So then the host can't use it. And you configure the LAN interface of the pfSense VM as host-only. So now the host machine (your workspace) can reach the Internet only through the VPN client in the pfSense VM.
Or you can just make sure that WebRTC is disabled.
Also uBlock has an option "Prevent WebRTC from leaking IP adresses".
WebRTC should be disabled by default or firefox should ask explicitly like with webcam-access.
There have already been reports where sites use your browser as a peer in a P2P-network (without your consent). This can be really problematic depending on where you live.