Office Mode IP Address Lease Duration
When a remote user's machine is assigned an Office mode IP address, that machine can use it for a certain amount of time. This time period is called the "IP address lease duration." The remote client automatically asks for a lease renewal after half of the IP lease duration period has elapsed. If the IP lease duration time is set to 60 minutes, a renewal request is sent after 30 minutes. If a renewal is given, the client will request a renewal again after 30 minutes. If the renewal fails, the client attempts again after half of the remaining time, for example, 15 minutes, then 7.5 minutes, and so on. If no renewal is given and the 60 minutes of the lease duration times out, the tunnel link terminates. To renew the connection the remote user must reconnect to the Security Gateway. Upon reconnection, an IKE renegotiation is initiated and a new tunnel created.
When the IP address is allocated from a predefined IP pool on the Security Gateway, the Security Gateway determines the IP lease duration period. The default is 15 minutes.
When using a DHCP server to assign IP addresses to users, the DHCP server's configuration determines the IP lease duration. When a user disconnects and reconnects to the Security Gateway within a short period of time, it is likely that the user will get the same IP address as before.