I have a CPU 315-2 PN/DP with a running TCP (compatibility mode) passive connection using TCON, TSEND, TRCV, TDISCON. The remote partner is not set (TCON.CONNECT.rem_staddr_len = 0), so everybody is allowed to connect.

How can I find out the remote partner’s IP address, when he connects? The address is only visible under Module Information/Communication/Open communication via Industrial Ethernet/Diagnostics. It is possible to get the partner’s IP of a UDP communication, but how to get it on TCP?

I would like to distinguish the clients when there are more connections on the same port (with two TCON IDs of course).

with who does your plc communicate ?! 

Janko

then your should already know ip of pc..., anyway I think that there is no possibility of understanding what is the IP of partner, because you already know that first three numbers has to be the same as of plc's ip... (192.168.0.xxx for example). Another thing that you might want to do is to specify the ip of partner in TCON_PAR DB.

Hope this helps you.

Janko

Thank you for your replies, but this is not the point. I don’t want to specify the IP address of the PC before creating the connection, this is obvious and easy to do.

I want to find out the IP address of the partner of an existing connection, which btw. doesn’t necessary need to be in the same subnet (think about routing). I need it for diagnostic purposes (display on the OP, logging) and possibly for blocking unwanted access or for filtering data sent to a specific client.

Any suggestiions how to find out the connection data?

Hi, 

if you are talking about firewall the only thing i know i usage of CP x34 modules... I think that there is no possibility of filtering connection using only cpu. 

Janko