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Windows 11 PC getting additional 0.0.0.0 default gateway
I run a self built router setup, running Kea as a DHCP server, firewalld for managing the firewall, and dns hosted elsewhere. Its currently running in a test configuration behind a known good network, since I'm still working out the details
I currently have a windows 11 desktop plugged in as a client - it has a reserved IP on kea's configuration.
Its also connected to another network - that'll connect to the internet but due to the test network being 10 gig, that'll be preferred as long as I can get an IP on the test network.
There's a unifi switch in between. I'd some network issues I suspect was triggered by a raspberry pi I was testing and one of the symptoms was my desktop getting 0.0.0.0 and 10.0.0.1 as a default gateway - this is the output for that adaptor from ipconfig. PC and router settings are identical throughout except when I changed things for testing. The configurations of kea and firewalld before, when the problem started, and after are identical.
This broke routing and other things. 0.0.0.0 isn't configured in kea as a "router" and there's no reason it should have been picked up as an IP. I've also literally never seen 2 default gateways even when trying to do so on purpose. Attempts to traceroute out broke, as well as connecting to the router's IP via SSH.
So what could have happened here, and what temporarily broke my network?
- firewall and DHCP configurations have not changed during this time
- the one change pre-and post breakage was one raspberry pi model A being plugged in with a fresh install of pi os. I'm probably retesting this to see if I can replicate the breakage once I'm sure things are stable