Can you recommend a good book on the subject? Especially one which includes the transitioning pitfalls. I have been living through it all and can get a little confused as to what is status quo. First I heard that SLAAC was great. Then came DHCPv6 and some complained it was an ill concieved bandaid. Now I was under the impression that link local addresses would make my day easier but not you indicate that ULAs are the way to go.

All of this is made much harder by ISPs actively fighting IPv6 adoption. They have the usual moat babble that users do not request it. But in my case they even blocked /protocol/ 40. This was not documented anywhere. Imagine the layers of support I had to work through. Imagine working with new technology and be sure enough that you have exhausted all other possibilities. So learning practical IPv6 has been an uphill struggle for me. Years ago I had a SixXS tunnel going before major adoption took off. Now I am living in another place and wanted to look at it seriously. SixXS was no more so I went with HE. To my dismay dark corners of the Internet have abused these offerings so I have my tunnel disabled most of the time as it gives too much grief. And I have even worked in operations at a large ISP in the 90s. Adoption is not easy even for the willing.

But the reason? No one here seems to mention it: Money. There are no technical excuses left. But it is surely a nice moat.

Sorry for the rant! A good up to date book recommendation would be appreciated :-)

Thew rant is justified. Link local addresses were cool at first but then people realized they were actually a really bad leak of layer 2 into layer 3 and that you need something truly layer 3 but for private networks and abstracted over link hardware. I’ve just read the RFCs and have first hand experience working with a home router mesh networking product that supports IPv6 and uses link local addresses to bootstrap the management layer.

SLAAC is still the way to go downstream, or upstream when you don’t have an ISP doing prefix delegation with DHCPv6. ISPs just want more downward control probably for money and maybe a tiny bit for legal/abuse/security reasons, so they use dhcpv6. secure neighbor discovery would probably be the non-dhcpv6 solution to having link-layer identity, would be cool if isps gave you slaac+send as an alternative to dhcpv6, but that would require average consumers to understand certificates and pki, so fat chance.

edit:

so there’s address assignment and addresses themselves. slaac and dhcpv6 are assignment mechanisms. global, ula, link-local are types of addresses. so the story isn’t really that people hopped from slaac to dhcpv6 to link-local to ula. it’s that slaac is how you configure ipv6 addresses in high trust environments and dhcpv6 came later when isps needed more control rolling things out. I actually don’t understand what problem dhcpv6 solves other than isps presumably wanting to spend less effort to work v6 into their existing systems than to write new utility that monitors their last mile segments for router solicitations and maps to customers that way. slaac is still the preferred mechanism.

then there’s the link-local to ULA transition . really it’s the site-local to ula transition. site local was the indended way to have a private network but had problems. so ot was deptecated. i think maybe before there was a ULA alternative, for link-local made sense in the scene for a hot minute, but now ULAs are here amd they are designed specifically for private site-wide addressing. so thats what is preferred for that.

slaac+ula for private home stuff

nat and dhcp are bad relics

whatever your isp supports/required to get a global prefix delegation. fun fact, you’re supposed to be handed a /48 by your isp so you can have the freedom of 65k subnets but few are so generous.