Subscriber Services: Asymmetric DHCP leasing

You can configure an override to the DHCP configuration -- typically on the relay agent -- to send a shorter (asymmetric) lease to a DHCP client than the lease granted by the DHCP local server. When the local server sends a client an acknowledgment packet in response to the client's offer, the relay agent generates a new acknowledgment packet with the shorter time that you configured. When the client requests a lease renewal, the relay agent re-creates the short lease based on the original lease, rather than passing the request back to the local server. The relay agent continues to renew the shorter lease until the long lease renew time expires, at which time the asymmetric lease is no longer valid. Subsequent renewal requests from the client are forwarded to the server for consideration. If the client does not renew the lease before the short lease renew time expires, then the lease is considered to be abandoned by the client. The address is freed earlier than it would be if the granted lease was used. This feature is available for both DHCPv4 and DHCPv6 configurations.