Or try to use an ethernet sniffer like wireshark.īut use a Hub Device (not a switch) for sniffing, you then are able to see both - MAC Adress and IP Adress. Step 7 tries to connect to the PLC using ISO protocol, and displays infos of your CP343-1. I think that should work, when you connect to the subnet with any ip-adress. So you could use Step 7 Function target-system - edit ethernet device. You see - thatsmore complex, you need to know mor about IP Adresses and IP subnetting.īuti can imagine what you want - handle a CPU although you don´t have infos or S7-Project! Try it with a Windows XP System with Internet connection These are services for converting MAC Adresses to IP Adresses RARP and IP Adresses to MAC Adresses ARP in an subnet. Or actual RARP (Reverse Adress Resolution Protocol) The service you need is called ARP (Adress Resolution Protocol) You´re able to assign any IP Adress to an ethernet device.īut you should use Private IP Adresses from the Pool of Private Class A (10.0.0.0|8) or Private Class C IP Adresses (192.168.0.0|24) So I´m afraidthere´s no way to CALCULATE an ip adress from mac adress or reverse!Įvery Ethernet device should have a worldwide unique MAC Adress.

What if I dont know IP address of CPU315 or CP341 card