← Port Encyclopedia
721
Port-721
TCP
System Low Risk
Reserved or unassigned port 721 — may appear in network scans as open, closed, or filtered

🔍 How to Scan Port 721

nmap -sV -p 721 target
nmap -sV -sC --script=banner -p 721 target
nc -zv target 721

🛡️ Security Considerations

  • Scan port 721 with nmap -sV to identify the exact service and version
  • If Port-721 is not needed, close or firewall this port immediately
  • Check for default credentials if a management interface runs on this port
  • Use searchsploit port-721 to find known exploits
  • Monitor traffic on port 721 with Wireshark or tcpdump for anomalies
  • Ensure the service is patched to the latest version to prevent known CVE exploitation

🔗 Related System Ports

Port 1
TCPMUX
Port 5
RJE
Port 7
Echo
Port 9
Discard
Port 11
systat
Port 13
Daytime
Port 17
QOTD
Port 19
Chargen
Port 37
Time
Port 79
Finger
Port 111
RPCbind
Port 113
Ident

📍 Nearby Ports

Port 716
Port-716
Port 717
Port-717
Port 718
Port-718
Port 719
Port-719
Port 720
Port-720
Port 722
Port-722
Port 723
Port-723
Port 724
Port-724
Port 725
Port-725
Port 726
Port-726
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