On 1/06/22 17:16, Lawrence D'Oliveiro wrote:
On Wed, 01 Jun 2022 16:32:50 +1200, Eric Light wrote:
I've definitely seen 127.0.1.1 and 127.0.0.2 in use...
I, too, have seen 127.0.0.2, at least. Never understood why.
systemd's resolver also listens on 127.0.0.53:53. This will ensure it avoids any other resolver, listening on only localhost. I read that having the local name on 127.0.0.2 (or …1.1) helped by having the host "one IP away". I vaguely recall in the dim past that having the hostname on a separate IP than "loopback" (127.0.0.1) helped some software (but I've lost the full recollection and my google-fu is lacking…) When I first read the article, I did ponder why attempt to free up IPv4, instead of looking at IPv6. 30+years ago, I recall software having issues where it hadn't caught up with CIDR - is it likely that opening up 127/8, multicast ranges et al. is going to expose assumptions made in those routers that haven't been updated in a long time?