Ports 23 (Telnet), 445 (SMB), 3389 (RDP) and 5900 (VNC) are among the riskiest to leave open. Check port forwarding, UPnP and DMZ settings, then confirm with an external port scan.
Check firmware monthly, patch critical flaws right away, and plan new hardware every 3 to 5 years, sooner if support ends. After updating, confirm the version, DNS and port forwarding.
Review why SMB port 445 should not be internet-exposed, what to check in router and firewall settings, and where MyIPScan fits as public IP context only.