it's fun to have this discussion all over again, for some value of fun.
in this case, i agree with john, we do not make it easy. that so many
reply with 'advice' qed.
but for some possibly new data on the embarrassing large extent of cgn
deployment, here is the book
"A Multi-perspective Analysis of Carrier-Grade NAT Deployment:"
Philipp Richter (TU Berlin), Florian Wohlfart (Technische
Universität München), Narseo Vallina-Rodriguez (ICSI), Mark Allman
(ICSI), Randy Bush (Internet Initiative Japan), Anja Feldmann (TU
Berlin), Christian Kreibich (ICSI /Lastline), Nicholas Weaver
(ICSI), Vern Paxson (ICSI / UC Berkeley)
https://dl.acm.org/citation.cfm?id=2987474 (no paywall)
and the movie
https://ripe73.ripe.net/archives/video/1244/
randy