EtherNet/IP not using requested port

Software version : 5.11.8 (and also 5.9 Robot and URSim)
Robot generation : 10e
Steps to reproduce :

  • Enable EtherNet/IP in installation node
  • From Originator register session and start Forward_Open with a non standard UDP port for originator

Expected behavior :
Robot should use specified port.
According to “THE CIP NETWORKS LIBRARY” Volume 2 Edition 1.4 in 3-3.9.1:

For point-to-point connections, the consumer shall choose a UDP port number to which the
connected data shall be sent. The port number may be the registered port number (0x08AE) or
may be a port number chosen by the consumer. The port number shall be encoded in a
Sockaddr Info item and shall be sent with the Forward_Open (if the connection originator is the

Actual behavior :
Reply from robot state that standard port (2222) will be used, and actual implicit messages will be to this port regardless of the one specified.

My library is working using non standard port for implicit message (Forward_Open).
I tested other devices and it’s working: Siemens, Turck Banner