6 min read
2026-02-14
Every open port is a potential entry point for an attack. Keep only the necessary ones open.
Move SSH from port 22 to a non-standard one (e.g., 2222). This is not full protection but reduces the number of automated attacks.
Configure "deny all, allow specific" rules. This is more reliable than blocking individual ports.
Conduct periodic audits of open ports on servers. An unexpectedly open port may indicate a compromise.
Databases (3306, 5432) and admin interfaces should never be accessible from the internet.
Set up logging of connection attempts to closed ports. This helps detect reconnaissance and scanning.
Vulnerabilities in software listening on a port are more dangerous than the open port itself. Timely updates are critical.
Check port assignments in the Port List.
See also: IP Calculator, MAC Lookup