Indeed, and those who like to blindly drop all ICMP are gonna be hurting when it comes time to deploy IPv6. As noted in RFC4890 [0], "ICMPv6 is essential to th

Indeed, and those who like to blindly drop all ICMP are gonna be hurting when it comes time to deploy IPv6. As noted in RFC4890 [0], "ICMPv6 is essential to the functioning of IPv6 ... Filtering strategies designed for the corresponding protocol, ICMP, in IPv4 networks are not directly applicable." So, if you currently just drop all ICMP at the edge, you might as well get used to doing it the right way now and save yourself some trouble in the future. [0]: https://www.ietf.org/rfc/rfc4890.txt https://www.ietf.org/rfc/rfc4890.txt