Simple Answer
No, while this is possible, it is unrealistic and not needed. See my longer explanation below. Also, if you really want to do this, although it is possible through QUIC, it’s not likely to be needed (as explained below).
Longer Answer/Question to think about
In short, this is not a needed feature of WebRTC. Let me ask you a question:
Alice and Bob are in a data channel, exchanging chat messages over WebRTC. To create a WebRTC connection, you need to use an ice server ( first link, second link ) to get both Alice and Bob to, to quote Wikipedia:
...to find ways for the two computers to talk to each other as directly as possible..
This means that it will use Alice’s current IP address to make an offer to Bob through a STUN or TURN server. If, like you said, Alice were to change IP addresses, she would need to change location. That means that she will need to move a sufficient distance so that the IP address will change. In practice, this probably means that she goes in a car and drives somewhere. If not, she calls an Uber or a cab or rides her bike. In most of these scenarios, she will need to close her computer, hence ending the p2p connection. If, by some weird wizardry, she doesn’t close her computer/the connection, the browser will very likely refresh, hence re-connecting to the WebRTC data channel from the new IP address. When will you need to create a WebRTC data channel and handle IP changes? Long explanation coming to a conclusion, clients changing IP addresses without ending/resetting the connect just doesn’t happen in practice.
If you want to look into other alternatives, here are some examples:
ALTERNATIVES
Adding an IP event listener ★
Now this isn’t an actual global variable that you can check, but you can use an online API (some are listed here) to check the user’s IP address, store it in a variable (or localStorage), and check if the IP changes. In a loop, you would do some simple logic to check If it does, you reset the WebRTC connection, if not, you keep the loop going.
Using a “piping” server
You can set up a simple chat by using a http/https server, already set up, explained here, called a piping server. You can look at the article for more information, but it promotes a serverless chat system (can be used without creating a server) that isn’t exposed to the difficulties of changing IP addresses. However, you need to know the peer’s ID, and they need to know your ID, which effectively makes solution obsolete because you need to have some sort of communication before establishing this simple chat.
Using Node.js, Websockets, and/or Socket.io ★
If you want to create a simple chat app or create a data channel, Node.js and Socket.io is the way to go. This is super simple, however, it involves a server, which is why I left it for last. However, I highly recommend this for ease and simplicity, and is not reliant on IP addresses. See here for a very good starting immersion into Node.js and the Express framework. I am far from an expert from Websockets, but MDN is always a good place to start. However good Websockets are, I think that Socket.io is much easier for beginners, so if you are willing to sacrifice a bit of speed over simplicity, you should start here. These are all good server-side chat starting points.
Links
Simple Answer
QUIC connection migration
IP Listener
SO Question,
Ice Servers
MDN docs, Wikipedia
Piping Server
Simple article, Github repo
Node.js, Websockets, and Socket.io
Node.js and Express setup, Websocket intro, and Socket.io intro
All alternatives that are starred (★) are personally recommended.
