• Use probing. Redundancy mode: - When more than one IP address is available on a Security Gateway for VPN, Link Selection may employ the RDP probing method to determine which link will be used.The RDP probing method is implemented using a proprietary protocol that uses UDP port 259. This protocol is proprietary to Check Point and works only between Check Point entities. (Note that it does not comply with RDP as specified in RFC 908/1151). IP addresses you do not want to be examined (i.e., internal IP addresses) may be removed from the list of IP's to be examined. Once a Security Gateway maps the links' availability, a link selection per connection can be made according to the following redundancy modes:
    • High Availability (default setting) - In High Availability mode the VPN tunnel uses the first IP address to respond, or the primary IP address if a primary IP is configured and active. If the chosen IP address stops responding, the connection fails over to another responding IP address. If a primary IP address is configured, the VPN tunnel will stay on the backup IP address until the primary one becomes available again.
    • Load Sharing - In Load Sharing mode the encrypted traffic is distributed among all available links. Every new connection ready for encryption uses the next available link in a round robin manner. When a link becomes unavailable, all of its connections are distributed among the other available links. A link's availability is determined using RDP probing.