UDP 3702
Synopsis
- UDP port 3702 is used by WS-Discovery (Web Services Dynamic Discovery), implemented in Microsoft’s Web Services for Devices (WSD).
- Windows 7–11 use it via the Function Discovery services (fdPHost/FDResPub) and WSDAPI to discover WSD printers and scanners; the Windows Print Spooler “WSD Print” path relies on it.
- Many printers and MFPs listen on UDP 3702 for WSD discovery, including models from HP (LaserJet/OfficeJet), Canon (imageRUNNER), Epson (WorkForce), Brother, and Xerox.
- ONVIF-compliant IP cameras and NVRs use WS-Discovery on UDP 3702 for device discovery; vendors include Axis, Hikvision, Dahua, Bosch, Hanwha, and Uniview.
- Linux/NAS implementations such as wsdd/wsdd2 make Samba shares discoverable to Windows via WS-Discovery on UDP 3702 (seen on Synology, TrueNAS, OpenMediaVault, and common Linux distros).
- Video management and surveillance software (e.g., Milestone XProtect, Genetec Security Center, Blue Iris) uses WS-Discovery on 3702 to auto-discover ONVIF cameras on local networks.
- Vendor utilities and drivers (e.g., HP Smart/HP Scan, Epson Scan, Canon IJ/WSD drivers) use WS-Discovery on 3702 to find devices.
- Security note: WS-Discovery on UDP 3702 has been abused for reflection/amplification DDoS attacks, especially via exposed ONVIF/WSD-enabled devices that answer unauthenticated probes.
Observed activity
Last 30 days
Detailed chart