[victorhooi]

One thing I can't figure out with Nebula is - how do you join multiple different networks?

For example, I have a personal laptop - I want to join two different networks, that are for two different purposes, and be able to talk to hosts in each? (But hosts in each should not be able to talk to hosts in the other)

[sascha_sl]

It doesn't do that, you get one CA per instance.

You can run multiple instances though.

[rhuber]

Actually it does do that, you can trust multiple CAs in a single instance and even write firewalls scoped to CAs.