Throughout the operation of an active VPN connection, the stations constantly check whether communications are subject to a previously agreed security association (SA). If the framework conditions change (e. g. a change of the client's IP address through relocation to a different radio cell), you must renegotiate this security association. This is done with "rekeying".
As of version 2.30, the LANCOM Advanced VPN Client transmits a special identification number (ID) during phase 1 rekeying. A LANCOM VPN gateway detects rekeying based on this ID and links the previous security association with the client. This makes re-authentication unnecessary.