It’s called a STUN (Session Traversal Utilities for Nat) IP address request for WebRTC (WebRTC is a peer to peer communications protocol allowing an easy browser voice and video communication). They are made outside of the XML/Http request procedure which makes it not even able to be seen in the developer console. These requests allow online tracking if an advertiser has a STUN server set with a wildcard domain. It is used for P2P media chat purposes, but this should be set to false and only prompt a user to enable it when this functionality is needed.
Currently, this is allowed in Firefox and Chrome through their implementation of WebRTC. So far, it is only possible to disable it in Firefox, while Chrome offers this extension.
To disable the WebRTC functionality, follow these steps on Firefox:
Type “about:config” in a new tab,
Find “media.peerconnection.enabled” and toggle it to false:
To test if your browser is vulnerable to this type of attack, you can visit this site https://diafygi.github.io/webrtc-ips/.