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.
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.