1. Peer-to-peer and client-server.
2. (a) IPsec, L2TP, and OpenVPN. (b) L2TP.
3.  Authentication Headers (AH), Encapsulating Security Protocol (ESP), and Security Association (SA).
4. (a) The connection will fail because when the Key Exchange version is set to Auto and pfSense is the initiator, it will use IKEv2 (since the other firewall is using IKEv1, there will be a mismatch). (b) The connection will succeed because pfSense as the initiator will again use IKEv2, and the protocols will match.
5. (a) 500; (b) 1194.
6. Challenge-Handshake Authentication Protocol (CHAP), MS-CHAPv2, and Password Authentication Protocol (PAP).
7. Elliptic-curve Diffie-Hellman (ECDH).
8. Lightweight Directory Access Protocol (LDAP) and Remote Authentication Dial-In User Protocol (RADIUS).