Up until this point in the book, we've focused solely on IPv4 networking. However, IPv4 is not the only IP protocol available to us. Although IPv4 is still the most widely understood protocol, IPv6 has started to gain significant attraction. Public IPv4 space is exhausted and many are starting to foresee issues with running out of private IPv4 allocations as well. IPv6 looks to overcome this problem by defining a much larger set of usable IP space. However, IPv6 does some things differently from IPv4 making some believe that implementing IPv6 would be cumbersome. I would argue that as you look to deploy container technology, you should also be looking at how to effectively leverage IPv6. Although IPv6 is a different animal, it will soon become a requirement in many networks. With containers representing the possibility of introducing many more IP endpoints on your network making the transition sooner rather than later is a good idea. In this chapter, we'll look at what IPv6 features Docker currently supports.