Nmap port states
| Open | Indicates that an application on the target system is actively accepting connections (TCP/UDP/SCTP) on that port. |
| Closed | Indicates there isn’t any application listening on that port. |
| Filtered | Nmap cannot to determine the port status as the nmap probes are not able to reach the port. Such filtering could be from a network firewall, host firewall software or routers. |
| Unfiltered | The port is accessible and responsive to Nmap probes, however, it’s not possible for Nmap to determine whether the port is open or closed.Scanning these ports with other scan types such as Window scan, SYN scan, or FIN scan, may help to check if the port is open. |
| Open/Filtered | Nmap could not determine the actual state of the port. The port is either open or filtered. |
| Closed/Filtered | Nmap could not determine the actual state of the port. The port is either closed or filtered. |