Comment by kuon

> What’s the advantage for me with ipv6?

I don't know what your situation is, but I'm a regular programmer-type employee who has been through more mergers than I ever expected to. Every company I've been at used IPv4 addresses for the systems on their internal networks.

I've observed that one of the things that takes the longest to sort out after the merger "closed" (or whatever they call the "It's official. We now own you." phase) is merging the two company's internal networks. While some of the delay comes from removing redundant systems and "harmonizing" security policies and the like, the IT folks who I talked to about the process always told me that the thing that takes by far the longest time is IP address management... specifically, having to renumber networks and the systems on them, and reconfigure or reinstall the software on them to account for the renumbering.

If you're using IPv6's ULA addressing for your internal networks, the odds of an address collision are very nearly zero. With IPv4 addressing... unless your network is tiny, the odds appear to be very nearly one.

I don't know you as well as I should :) I should say I'm not that interested in selling something that is both free and 'politically' loaded.

People have made up their minds, they'll pick it up or they won't. No "skin off my teeth" at all. Implementation details matter to those who care. They have their reasons, I'm not one to question them.

One of the things I like about v6 is it allows us to give up the charade or vanity of addressing. At least minify it. One can define classes of networks and simply identify hosts by MAC (or FQDN assuming an AAAA record).

I already have to tote that information around to configure them. Having a v4 address can be seen as duplicating the role of identity, while risking conflict. Outright removal of v4 may offer benefits in some scenarios.

Now... 'conflict' is how BGP anycast literally works. Two or more hosts announce the same location. There are perfectly valid reasons to still use v4, neither precludes the other.

One past employer of a friend has an internal network using IPv4 only. Every night a database query runs on one database and updates a second database based on the results (a DSS updated from a data warehouse, I think). One of the TCP connections involved goes through five levels of NAT, internally to the company.

No one on the team liked adding the fifth NAT, but no one felt confident enough to undo any of the old NATs either.

If you use IPv6 internally you don't dig yourself into holes like that one. You have enough addresses that you can choose clarity and maintainability in little day-to-day choices and a few years later that clarity has added up.