RSlinx, OpenVPN

[*bj]

Hi everybody.

I have a problem discovering my devices using RSlinx.
My setup is:
- MicroLogix 1400 (192.168.132.2) connected via ethernet to GPRS gateway (192.168.132.1).
- Another MicroLogix 1400 (192.168.131.2) connected via ethernet to another GPRS gateway (192.168.131.1).
- PC with installed OpenVPN connected to server, which provids static IP adresses for GPRS gateways.

I made a simple program to communicate between PLCs using MSG instruction and is working fine. Also, I have a laptop (192.168.132.11) connected in 192.168.132.x subnetwork, with installed RSlinx. From my laptop I can se both PLCs in RSlinx, using "Ethernet devices" driver.

Problem is I would like to reach PLCs through RSlinx on my PC using OpenVPN. I can successfully ping both PLCs from my PC. I have found several threads here and tried using Ethernet/IP driver, or adding :EIP sufix on IP adresses in Ethernet devices driver, but no luck.

I kindly ask for some help regarding this matter.

 

[Ken Roach]

Ports and Subnets matter too

Because you can browse both controllers using your locally-connected laptop with 192.168.132.11, then you must have the subnet masks or default gateways properly configured so that it can communicate with both the 192.168.132.x asd 192.168.131.x subnets.

I suspect you will have to configure the OpenVPN or the GPRS devices to pass TCP Port 44818, which is used by Allen-Bradley controllers.

Instead of using the ordinary ICMP Ping function from the computer's command line, try using the TCPing utility (from Eli Fulkerson), specifying Port 44818.

Once you can get a connection to Port 44818, use the Ethernet Devices driver with :EIP appended to the IP address.

The EtherNet/IP driver uses a broadcast packet for browsing, and will very likely not work with GPRS or with a VPN.

 

[*bj]

Ken, thank you for your answer.

I tried TCPing tool on port 44818 and had no answer. For now, I'm still searching where that port needs to be opened.

 

[*bj]

Well, following Kens advice and port 44818, problem was found in server.
Server firewall would not allow traffic through, but adding a tunnel from OpenVPN solved the problem.

 

[Ken Roach]

Thank you for posting the followup !

 

[cdran]

tcping replies:

Probing 192.168.1.97:44818/tcp - Port is open - time=29.751ms

but should that be udp instead of tcp?

 

[Ken Roach]

Welcome to the forum ! Ideally, create a new thread and reference very old ones only by linking. We're not as sophisticated a forum as Reddit or something similar that can archive or lock old posts.

When you're using the "EtherNet/IP" automatic browsing driver, it's very difficult to make it work with VPNs, routers, or gateways. It uses a TCP Broadcast.

When using the "Ethernet Devices" driver or something else that manually specifies the target IP address, the port is definitely TCP Port 44818.

Sorta-related: this week I managed to fault a customer PLC with a Duplicate IP Address conflict by inadvertently connecting to my home network using ZeroTier from across the country. Pretty impressed with myself actually.

 

[ASF]

Downtime cause: Ken's smart refrigerator

 

[Jeev]

We have had this previously with consumer devices and small operations alike running on 192.168.x.x. After that, employees supporting equipment remotely changed their home devices to be on relatively uncommon subnets.