Sky UK T-Systems PPPoE clients have the functionality to detect path unavailability by using PPP Keepalives. IPoE does not have this functionality, and it's not specified when an IPoE client should consider its WAN connectivity down, unless there is a physical layer link down event. This document describes a way for IPoE clients to achieve connectivity validation, similar to that of PPPoE, by using existing ARP and Neighbor Discovery functions.