← Port Encyclopedia
691

MS-Exchange

TCP
Email Medium Risk
MS Exchange routing — Microsoft Exchange server communication

🔍 How to Scan Port 691

nmap -sV -p 691 target
nmap -sV -sC --script=banner -p 691 target
nc -zv target 691

🛡️ Security Considerations

  • Scan port 691 with nmap -sV to identify the exact service and version
  • If MS-Exchange is not needed, close or firewall this port immediately
  • Check for default credentials if a management interface runs on this port
  • Use searchsploit ms-exchange to find known exploits
  • Monitor traffic on port 691 with Wireshark or tcpdump for anomalies
  • Ensure the service is patched to the latest version to prevent known CVE exploitation

🔗 Related Email Ports

Port 25
SMTP
Port 110
POP3
Port 143
IMAP
Port 465
SMTPS
Port 587
SMTP-Submission
Port 993
IMAPS
Port 995
POP3S
Port 2525
SMTP-Alt
Port 7071
Zimbra
Port 7078
Zimbra-LMTP

📍 Nearby Ports

Port 686
Port-686
Port 687
Port-687
Port 688
Port-688
Port 689
Port-689
Port 690
Port-690
Port 692
Port-692
Port 693
Port-693
Port 694
Port-694
Port 695
Port-695
Port 696
Port-696
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