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Ubuntu 20.04 Networking - can't get and outbound and inbound connection at the same time?

cn flag

I have a Ubuntu 20.04 VM that's had a solid connection for months. I recently changed my network subnet (from 192.168.7.x to 192.168.10.x). I made sure that netplan config has dhcp set to true, and set a reserved address through my router for the machine. It does get that IP address, but now it can't reach the internet. If I delete all firewall rules and add back just the ACCEPT for INPUT, FORWARD, and OUTPUT, it can then reach the internet, but I can't access it over my network via ping, ssh, or any of the docker web applications it's running. If I reboot the server, it will still get the reserved IP, but then it can't reach the internet again.

Am I losing my mind? Is there a way to just do a clean reset of the networking? I have checked Proxmox to make sure there is no firewall running on the data center, proxmox, or vm level as well.

Any help is greatly appreciated.

Doug Smythies avatar
gn flag
It sounds as though your issue is within your default firewall rule set, so please show us that content. It also sounds as though those rules are iptables based so show us the outputs for `sudo iptables -xvnL` and `sudo iptables -t nat -xvnL`.
cn flag
I can run those commands, and I see a lot of iptables rules, but I have no way to copy it, as I'm having to use the Proxmox console in the browser, and there's no highlight option, and I can reach my other machines from that VM on the network, so I can't scp out a text file I made of the output either. Any thoughts on how I could get this for you?
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