UDP 391
Synopsis
- UDP port 391 is registered by IANA as synotics-relay.
- It was used by SynOptics/Bay Networks/Nortel Optivity network management software and the management agents on their network devices for proprietary relay communications, typically alongside UDP 392 (synotics-broker).
- Real-world examples include SynOptics LattisHub hubs and BayStack switches managed by Optivity NMS, which listened on UDP/391 for management-related messaging.
- This usage is largely legacy and uncommon in modern networks; it is not broadly associated with exploitation.
Observed activity
Last 30 days
Detailed chart