5353
mDNS (Multicast DNS)
Low RiskUDP — DNS
Port Overview
Port Number
5353
Service Name
mDNS (Multicast DNS)
Transport Protocol
UDP
Category
DNS
Security Risk
Low
Port Range
Registered (1024-49151)
What is Port 5353?
Port 5353 is used by mDNS (Multicast DNS), which enables zero-configuration DNS name resolution on local networks without a central DNS server. Apple's Bonjour and Linux's Avahi implement mDNS to allow devices to discover services like printers, AirPlay, and Chromecast. Queries and responses are sent to the multicast address 224.0.0.251.
UDP
DNS
Commonly Used
Security Considerations
Port 5353 (mDNS (Multicast DNS)) is classified as low risk. This service uses encryption or has a minimal attack surface, making it relatively safe to expose.
Recommendation: Standard security practices apply. Keep software updated and monitor access.