639
MSDP
Medium RiskTCP — Other
Port Overview
Port Number
639
Service Name
MSDP
Transport Protocol
TCP
Category
Other
Security Risk
Medium
Port Range
Well-Known (0-1023)
What is Port 639?
Multicast Source Discovery Protocol (MSDP), defined in RFC 3618, used by PIM-SM to share active multicast source information between Rendezvous Points across different PIM domains.
TCP
Other
Security Considerations
Port 639 (MSDP) is classified as medium risk. While this service is commonly exposed, consider using encrypted alternatives where available.
Recommendation: Keep the service updated. Monitor logs for unusual activity.