← Port Encyclopedia
421

Port-421

TCP
System Low Risk
Reserved or unassigned port 421 — may appear in network scans as open, closed, or filtered

🔍 How to Scan Port 421

nmap -sV -p 421 target
nmap -sV -sC --script=banner -p 421 target
nc -zv target 421

🛡️ Security Considerations

  • Scan port 421 with nmap -sV to identify the exact service and version
  • If Port-421 is not needed, close or firewall this port immediately
  • Check for default credentials if a management interface runs on this port
  • Use searchsploit port-421 to find known exploits
  • Monitor traffic on port 421 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 416
Port-416
Port 417
Port-417
Port 418
Port-418
Port 419
Port-419
Port 420
Port-420
Port 422
Port-422
Port 423
Port-423
Port 424
Port-424
Port 425
Port-425
Port 426
Port-426
📚 Learn Network Scanning — Free Course
Found this useful? Share it.
Keep going
Free coursesStructured, day-by-day tracks Free hacking labsPractice in your browser, no setup Attack SimulatorHands-on challenges in your browser
Make it count. Join free to earn XP for what you read and solve, keep a streak, and track your progress.
Join free