Client aware dhcp lease managment

Abstract

Managing DHCP address leases based on client properties. A DHCP server may allocate a short DHCP lease to a client device based on client properties. These client properties may include client device type, such as a type determined by OUI or OUI lookup, by client device characteristics, or by client position. Depending on client device properties, the client device is issued an address with a short lease time, or a long lease time. In the case of client activity, a DHCP server responds to initial requests for addresses by allocating an IP address with a short lease time. When the DHCP server receives a renewal request, it checks to see if the client has generated more than a predetermined amount of traffic. If the client has generated traffic exceeding this threshold level, the lease is renewed for a longer period. If the client traffic has not met the threshold level, the lease is renewed with the short lease time. Issuing addresses with short lease times removes inactive devices aggressively, returning addresses to the available lease pool. In an additional embodiment, a DHCP Relay mediates requests between clients and a DHCP server, rewriting lease times returned by the DHCP server to be short lease times. The DHCP Relay issues a DHCP Release to the DHCP server when a short lease to a client expires. The DHCP Relay mediates client DHCP Renew requests, renewing for a short lease time if the client has not generated traffic at the threshold level, and renewing for a long lease time if the client has generated traffic at or above the threshold level.