Sun Java System Web Proxy Server 4.0.2 2005Q4 Administration Guide

ICP

The Internet Cache Protocol (ICP) is a message-passing protocol that enables caches to communicate with one another. Caches can use ICP to send queries and replies about the existence of cached URLs and about the best locations from which to retrieve those URLs. You can enable ICP on the Configure System Preferences page. For more information on ICP, see Routing through ICP Neighborhoods.