For Linode Ubuntu 22.04 installations, at least, the default seems to be DHCP, even if the IP address is fixed. And I certainly wouldn't have thought anything about this, since even when using fixed IP addresses, I'm in the habit of using DHCP to provide a central source of IP address truth for my networks, to ease the pain of the inevitable renumbering.
That being said, maybe check if you have `dhclient`, `dhcpcd`, `systemd-resolved`, or (less likely) `dnsmasq` or `bind` running (htop / ps aux).
If you do, your instance may fall over after its DHCP lease expires and it then presumably fails to acquire a new one and goes all 169.254.x.x on you.
The possible counterpoint / information-vacuum bit here is that I don't know what the DHCP lease time is, so the expiry may already have happened.
IOW, apparently this started 4h ago, and so the last leases were presumably issued 4h ago, and maybe the lease length is 1h, so everything's already as dead as it's going to get, so maybe if you're not already dead, you're fine.
We run some Windows instances, which were DHCP out of laziness. <facepalm> [edit: It's a PITA to fire up a Windows instance on Linode. Once working, switching out of DHCP is near the bottom of the todo list.]
I would expect the opposite. Doesn't DHCP make more sense, for example, if the user creates a snapshot and restores it with a new IP? I don't use Lenode, so I can't judge, but I would expect DHCP to be default.
Default created Debian based linodes use a static IP. How they assign you the IP is they have an initial network boot script that injects that static IP into your config.
I learned this because I wanted to test image recovery of deleted linode. When I restored it, I got a different IP address from linode (the static IP assigned to me), and I couldn't connect to it. Using the web console I found the IP address was hard coded to the old one still.
Just checked my tiny Nanode 1 GB image (Fremont) running Debian and it's indeed running dhclient. Still have access, but I need the instance this weekend for a virtual event. Kind of sucky timing for a potential outage, Linode.
Mine don't seem to be affected