MYTHOSLEARNING TOPIC
Linux security
Secure and troubleshoot services without losing access.
First security checks on a new Ubuntu server
Inventory the server, apply ordinary updates and reduce exposure without losing remote access.
Configure UFW without locking yourself out of SSH
Allow the real management path before enabling a deny-incoming policy.
Create and test an SSH key for Ubuntu access
Add key authentication first and verify it before removing password access.
Disable SSH password authentication safely on Ubuntu
Validate the effective configuration and test a fresh key-only login before closing access.
Find failed SSH logins on Ubuntu
Use service logs and time windows to distinguish routine errors from hostile patterns.
Find listening ports on Linux with ss
Identify protocol, bind address and owning process using the built-in socket inspection tool.
Check Ubuntu automatic security updates
Inspect unattended-upgrades, test its decision process and verify that important updates complete.
Understand Linux file permissions with a safe example
Practise owner, group and other permissions on a disposable file instead of changing system directories.
Troubleshoot a Linux service with journalctl
Read a bounded service timeline and check the result of a change without clearing evidence.
Configure a basic Fail2ban SSH jail on Ubuntu
Reduce repeated SSH authentication attempts while preserving your trusted management route.