We are working on an update to NetSim for CCNA to include FHRP and VPN functionality. FHRP, short for First Hop Redundancy Protocol, is used to provide redundancy up to the ISP. There are several FHRP protocols, of which HSRP (Hot Standby Router Protocol), GLBP (Gateway Load Balancing Protocol) and VRRP (Virtual Router Redundancy Protocol) are popular and being implemented in our NetSim.
Another addition would be VPN (short for Virtual Private Network) protocol that ensures encrypted tunnel between two end points. There are several types of VPN, of which Site-to-Site VPN and Site-to-Remote VPN are most widely used and being implemented. A Site-to-Site VPN is typically used between two offices (say head office and branch office) where as Remote-to-Site VPN is typically used by mobile commuters or smaller branch offices to connect to the head office. A VPN, as you might be knowing, encrypts the communication between two end points as defined by the communicating hosts.
Check out for updates.