The Untangle IPsec VPN is mainly used to provide site-to-site connections, which have many advantages over site-to-site solutions provided by OpenVPN including (but not limited to) better support for sharing, replication, LDAP protocols, and higher speed. Untangle IPsec VPN also provides the client-to-site connection method based on L2TP/IPsec. These features come at an additional cost as Untangle, Inc. provides the IPsec VPN as a paid module.
The IPsec VPN works on the OSI layer 3 (the network layer), which allows the encryption of information from layer 3 and the above layers. Thus, any eavesdropper will not be able to get any information about the packet, including the used ports and the IP addresses.
Unlike SSL/TLS VPN, the IPsec parties have no prior knowledge of each other, and the connection initiation process will not include any server certificates. The connection between the two parties is established using the Internet Key Exchange (IKE) protocol...