Re:Tell HN: IPv6-only still pretty much unusable
by oceanplexian on Friday December 09, 2022 @07:08AM
(#33920386)
NAT wasn’t started as a way to make the address space last longer. A few decades ago you could get hundreds of thousands of IP’s by filling out a form with ARIN without any serious justification if you wanted them. I worked at an ISP and IP’s weren’t a scarce resource.
NAT started because having a network didn’t mean you were necessarily participating in the Internet. Globally unique addresses weren’t that important. At some point you had this decentralized situation where local networks wanted to bridge their users address space to the Internet without renumbering everything and thus NAT was born.
Have you never had more than a handful of IPv4 addresses? IPv6 works the same in this regard as a router IPv4 network e.g. universities, large/old enterprises etc. NAT started as a workaround to make the available public address space last longer.
The address (and port) translation wasn't intended as a security feature on its own. These days lots of protocols automatically deal with NAT and mostly manage to establish bidirectional communication over UDP or TCP through NATs. I rather deal with stateful firewalls and public IPv6 addresses end to end instead of gluing the segments of flows between IPv4 translators back together.