There are many scenarios in which someone may want to connect to an Automation Runtime target, but they do not know the IP Address.
- Collecting a system dump
- Connecting via Automation Studio when SNMP is disabled
By connecting directly to the target and using Wireshark, we can find the IP address of the target.
Download Wireshark at https://wireshark.org/.
Install Wireshark per their installation instructions.
Ensure the PLC is powered on and physically connect directly from your laptop/PC to the target’s ETH port.
Select the Ethernet adapter responsible for the traffic between your laptop/pc and the target to begin capturing. In my case this is “Ethernet”.
Power cycle the target.
Wait a couple minutes until the target is fully booted and in a static state. Enter “arp” into the filter near the top of the window.
Look for the “ARP Announcement” message whose source begins with “B&RIndus_”. The info column should then tell you the IP address of the target. In my case it is 192.168.1.100.
In order to determine the correct adapter, we can use the “Network Connections” application in Windows.
In a scenario like mine seen above, it may be difficult to determine which adapter is directly connected to the target. I was able to determine that “Ethernet” was the correct adapter because unplugging the physical connection to the target led to the adapter reporting as “Network cable unplugged.”
Wireshark will automatically replace the start 00:60:65… of the MAC address with “B&RIndus_”. The MAC address of each Ethernet port is printed on the PLC. For this example, B&RIndus_30:12:45 represents the PLC with the MAC address 00:60:65:30:12:45.