Is the fact that your physical door locks and keys are only unique to your local region very much an implementation detail? No it's not. It's conceptually the same, but keys and locks are not globally secure. They're only locally secure.
Also IPv6: everything gets a globally routable address. Great so why do we need anything else? Well it turns out that in order to support all the different modes of network operation and all the different topologies and use cases, the Internet Protocol needs to support non-global scopes too. Arguing you can't have e.g. link-local security is absurd and rally quite green, from a networking professionals perspective.
Oh also IPSEC is part of IPv6 not just an afterthought like it was for IPv4. This makes it even more likely we'll see trusted network scopes sooner rather than never.
That is basically my point. People need to have ways to create local enclaves so it's impossible for packets to ever make their way into your zone. And wonxe you do that, local security is perfectly reasonable and desirable.
Also IPv6: everything gets a globally routable address. Great so why do we need anything else? Well it turns out that in order to support all the different modes of network operation and all the different topologies and use cases, the Internet Protocol needs to support non-global scopes too. Arguing you can't have e.g. link-local security is absurd and rally quite green, from a networking professionals perspective.
Oh also IPSEC is part of IPv6 not just an afterthought like it was for IPv4. This makes it even more likely we'll see trusted network scopes sooner rather than never.