Wow, thanks for the detailed rundown on multicast routing, Adrian. 

So anyone correct me if I'm wrong, but it sounds like is the current status quo is:

- You can run an SSB peer and give it a fixed IP on the mesh which your friends can sync with, if they know that IP.

- If that device is running Babel, they will also be able to keep syncing with it as you move around and connect with different mesh peers.

What people want to accomplish with multicast is:

- You can run an SSB peer, on a client device. Your friends will receive multicast traffic informing them of which IP your peer is currently accessible at.

Is this correct?