Started off by
- Enabling unattended updates
- Enable only ssh login with key
- Create user with sudo privileges
- Disable root login
- Enable ufw with necessary ports
- Disable ping
- Change ssh default port 21 to something else.
Got the ideas from networkchuck
Did this on the proxmox host as well as all VMs.
Any suggestions?
Don't expose unnecessary things to the internet, keep any client PCs patched, use some sort of malware protection ... and that's all you need to do.
All these VLANs are such are just overkill unless you're actively exposing things to the internet. They wind up breaking really useful stuff, especially stuff that relies on multicast.
Besides, that Chinese IoT device can't get hacked if it's not open to the 'net in the first place.