What is open on a server.
WHAT IS TYPICALLY OPEN
Web ports Mail ports Control panel ports Secure shell, on servers where it is enabled
WHAT SHOULD NOT BE OPEN
Anything not in use Database ports, externally Administrative services without restriction
WHY
Anything reachable is scanned continuously.
FOR SHARED HOSTING
The firewall is managed for you.
You do not configure server ports.
FOR A VPS OR DEDICATED SERVER
That responsibility is yours.
WHAT TO DO ON YOUR OWN SERVER
Allow only what is needed Restrict administrative access by source address where possible Keep the firewall enabled Review rules periodically
WHAT TO AVOID
Disabling the firewall to make something work Opening a range when one port is needed
WHAT TO CHECK
What is actually listening, and whether each should be.
WHAT TO DOCUMENT
Every rule and why it exists.
Undocumented rules accumulate and nobody removes them.
