Chapter 11 IPsec VPN for FortiOS 5.0 : IPsec VPN concepts : Authentication : Additional authentication
  
Additional authentication
To increase security, you can require additional means of authentication from users:
• an identifier, called a peer ID or a local ID
• extended authentication (XAUTH) which imposes an additional user name/password requirement
A Local ID is an alphanumeric value assigned in the Phase 1 configuration. The Local ID of a peer is called a Peer ID.