Internet-Security.com UDP port 34964 details

UDP port 34964 is used by PROFINET IO (industrial Ethernet) for real-time alarm/diagnostic messaging (often called RTA) between IO-Controllers (PLCs) and IO-Devices.
Siemens SIMATIC S7-1200/1500 PLCs communicating with ET 200 distributed I/O and SINAMICS drives use this port when configured for PROFINET.
Many third-party PROFINET devices—such as KUKA KRC4 robot controllers, Phoenix Contact Axioline I/O, and WAGO field I/O modules—also use UDP/34964 to exchange alarms/diagnostics with the controller.
Vendor firewall guides commonly require opening UDP 34962–34964 for PROFINET IO networks.

UDP 34964