The IPv6 Probe Option
Juniper Networks
Comcast
This document defines a new IPv6 option, called the Probe option. The Probe option elicits an ICMPv6 Parameter Problem message from all nodes that process it. When a node sends a packet that contains the Probe option and receives an ICMPv6 Parameter Problem message in response, it has verified the network's ability to convey packets that contain the Probe option.