WebRTC is a browser plugin that is typically utilized by web applications that require a fast direct connection. Since WebRTC establishes a connection through a UDP protocol, it is not routed through proxy servers that you may use in a browser. Websites may exploit this fact to reveal your real public and local IP addresses even if you are using a proxy. The same plugin can also be used to reveal your local IP addresses or track your media devices.
What WebRTC plugin leaks
- Public IP address(es)
- Local IP address(es)
- Media device numbers and hashes (covered on the Media devices page)
You can check what information about your WebRTC parameter the websites can retrieve from Browserleaks test website.
Multilogin allows you to control the WebRTC fingerprints of your browser profiles by providing three different modes of operation: Altered, Disabled and Real.
Altered mode (default setting)
In the altered mode WebRTC parameters Public IP and Local IP will be set on a browser profile launch to match the IP from browser profile configuration.
Public IP address
The "Fill on start based on external IP" option means when you launch a browser profile, it will first connect to our server. We will detect an actual external IP of this browser profile, return it back and set as WebRTC Public IP. If your IP changes in the middle of a session, WebRTC Public IP address will be immediately adjusted accordingly.
Leaving this option disabled means you will have to set WebRTC Public IP address manually.
Local IP address
Local IP address(es) is/are generated when you click "New browser profile" or "Get new fingerprint". You may also set Local IP address(es) manually. Some older browser profile may not have any Local IP addresses set.
Valid Local IP ranges
Local IP address must be within a valid local IP range. These are:
- 10.0.0.0 to 10.255.255.255
- 172.16.0.0 to 172.31.255.255
- 192.168.0.0 to 192.168.255.255
Typically, residential users have 0 in their C blocks (3rd number) and any number in D block (4th number). A corporate online user may have a different number other than zero in both C and D blocks.
Some examples of residential local IPs:
Some example of local IPs that typically corporate users have:
When the WebRTC parameter is disabled, browsers see that WebRTC plugin of a browser profile is completely set to off.
WebRTC plugin will be enabled and will leak your real IP addresses. This mode should be used if you are not connecting through proxies (e.g. you connect through a 3G/4G or a direct landline).
You can also mask or set Local IP address(es) manually (see the detailed explanation above).