CERNET Center/Tsinghua University CERNET Center/Tsinghua University Cisco Cisco APNIC A stateless IPv4/IPv6 translator may receive ICMPv6 packets containing non-IPv4-translatable addresses as the source. These packets should be passed across the translator as ICMP packets directed to the IPv4 destination. This document presents recommendations for source address translation in ICMPv6 headers to handle such cases. [STANDARDS-TRACK]