On Nov 19, 2021, at 07:23 , Dave Taht <dave.taht@gmail.com> wrote:
On Fri, Nov 19, 2021 at 7:00 AM Owen DeLong via NANOG <nanog@nanog.org> wrote:
Since, as you point out, use of the other addresses in 127.0.0.0/8 is not particularly widespread, having a prefix dedicated to that purpose globally vs. allowing each site that cares to choose their own doesn’t seem like the best tradeoff.
I would prefer to discuss the other drafts. However, - and this is not in the 127 draft, and is an opinion not shared with the other authors - I have a specific use case for making 127 "more routable", in that there is nowadays a twisty maze of microservices, bottled up in a variety of kubernetes containers, running on top of vms, on top of a hypervisor, that are often hooked together via rfc1918 addressing and NAT.
Trying to figure out that particular path, from within one of those containers, can be a PITA. The concept of 127 being local to a physical host (and routed internally, rather than natted), where those twisty maze of services ideally remains within that host, holds some appeal to me.
Couldn’t you do this with 169.254.0.0/16 (or IPv6 GUA or ULA) just as easily without the need to rewrite virtually every layer of the stack of miscellaneous software defined networking stuff you just listed? Owen