* [email protected] (Javier Gutierrez) [Thu 05 Oct 2023, 19:25 CEST]:
I have recently encountered some operational differences at my new
organization that are not what I have been exposed to before, where
the loopback of the core network devices is being set from RFC1918
while on the global routing table. I'm sure this is not a major
issue but I have mostly seen that ISPs use global IPs for loopbacks
on devices that would and hold global routing.
My question is, what is the most used or recommended way to do this,
if I continue to use RFC1918 I will save some very much desired
public address space, but would this come back to bite me in the
future?
The recommendation is to make Router-IDs globally unique. They're used
in collision detection. What if you and a peer pick the same non
globally unique address? Any session will never come up.
You need globally unique IP addresses on routers anyway, to send ICMP
error packets from.
-- Niels.
