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?
Opnsense firewall at perimeter…and that’s about it. Chances of anything getting in with no exposed ports is pretty slim so I don’t really bother with anything more.
For SSH exposed servers/VPS I do change the port though. Cut down log noise & maybe dodge the odd portscanner or two