← Port Encyclopedia
51
Port-51
TCP
System Low Risk
Reserved or unassigned port 51 — may appear in network scans as open, closed, or filtered

🔍 How to Scan Port 51

nmap -sV -p 51 target
nmap -sV -sC --script=banner -p 51 target
nc -zv target 51

🛡️ Security Considerations

  • Scan port 51 with nmap -sV to identify the exact service and version
  • If Port-51 is not needed, close or firewall this port immediately
  • Check for default credentials if a management interface runs on this port
  • Use searchsploit port-51 to find known exploits
  • Monitor traffic on port 51 with Wireshark or tcpdump for anomalies
  • Ensure the service is patched to the latest version to prevent known CVE exploitation

🔗 Related System Ports

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systat
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QOTD
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Finger
Port 111
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Ident

📍 Nearby Ports

Port 46
Port-46
Port 47
Port-47
Port 48
Port-48
Port 49
TACACS
Port 50
Port-50
Port 52
Port-52
Port 53
DNS
Port 54
Port-54
Port 55
Port-55
Port 56
Port-56
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