Analysis of Potential Solutions for Revealing a Host Identifier (HOST_ID) in Shared Address Deployments

This document is a collection of potential solutions for revealing a host identifier (denoted as HOST_ID) when a Carrier Grade NAT (CGN) or application proxies are involved in the path. This host identifier could be used by a remote server to sort packets according to the sending host. The host identifier must be unique to each host under the same shared IP address. This document analyzes a set of potential solutions for revealing a host identifier and does not recommend a particular solution, although it does highlight the hazards of some approaches.