This will break a significant number of existing deployments where people have come to depend on a feature in Linux where any address within 127.0.0.0/8 can be “listened” and operate as a valid loopback address without configuring the addresses individually as unicast on the interface. In fact, this is true of any prefix assigned to the loopback interface, but 127.0.0.0/8 is automatic and difficult to change. While I’m not sure this implementation in the Linux kernel was such a wonderful idea, it is widely deployed and in use in a number of environments. If we’re still using IPv4 widely enough that GUA space matters, we will have far bigger problems than the lack of available GUA for it. Owen
On Nov 17, 2021, at 16:15 , William Herrin <bill@herrin.us> wrote:
On Wed, Nov 17, 2021 at 3:31 PM Jay R. Ashworth <jra@baylink.com> wrote:
This seems like a really bad idea to me; am I really the only one who noticed?
https://www.ietf.org/id/draft-schoen-intarea-unicast-127-00.html
Hi Jay,
I think it's a good idea. It won't be usable any time in the next two decades but if we're still using IPv4 in two decades we'll be glad to have anything we can scrounge. Why not ask OS authors to start assigning 127.0.0.1/16 to loopback instead of 127.0.0.1/8?
Regards, Bill Herrin
-- William Herrin bill@herrin.us https://bill.herrin.us/