This post does not reflect the views on current, past or future employers. The opinions in this article are my own. This is a series of articles of my musings on why IPv6 failed. Previous article. Most networking protocols over the history of computer networking has failed. What makes up a successful protocol is defined in RFC5218. Personally I have worked on IPv6 standardisation and implementations since 1998. 27 years wasted then. At least I can claim to have learnt something along the way. Wonder what the inventors of ATM, X.25, IPX, DecNet, OSI, Apollo, … feel. :-) IPv6 is at least in good company. For some definition of “failed”, and reserve the right to take an antagonist position, and I do accept that there are valid use cases for IPv6.