GRE setup - how to connect two sites?

[torontob]

I have two pSense routers that are remote to each other. Both have dynamic IP addresses but use DDNS.

pfSense A: 192.168.10.0/24
pfSense B: 192.168.20.0/24

What is the process to connect the sites so clients of those networks can ping each other?

• GRE tunnel setup is not clear in wiki and in the book. What IPs go where when creatung the tunnel?

• Also, it's not clear what to do after creation of GRE - should interface for it be Enabled? Should there be a static IP assigned?

I am aware of security concerns and this is a lab testing environment.

I am appreciate some feedback.