XG5000: Host Table (IP Addresses) - LS Electric XGB PLC from AutomationDirect

in the Modern Age of remote access network security is a very important aspect of industrial controls the xgb PLC allows the user to set up host tables that prevent unauthorized remote communication access to the information in the PLC these host tables are lists of IP addresses that are allowed to access the ethernet ports each ethernet port has its own host table by default these host tables are disabled to allow any incoming IP address let's enable the host table for the internal ethernet interface on our CPU to do this we double click on the internal feet Network this will open the standard setting screen for this interface we can go to the security setting Tab and check the box for enable host table we can then enter the IP address of any device we want to allow a connection for up to 16 IP addresses can be registered in each host table let's add the IP address of a gs20 variable frequency drive we have connected if we select okay to accept the changes we can write this to the PLC it is important to note this applies to all incoming connections the interface will still respond to a ping test but it will not allow programming from a PC it also won't allow access from an external device over ethernet if the external device's IP address is not added to this list in our example we added the IP address of our drive but we didn't add the IP address of our computer running xg5000 if we attempt to connect to the PLC using the ethernet connection we get a failed connecting to the PLC error indicating the PLC refused the connection in this case the USB port on the CPU will still allow us to connect to disable the host table we connect to the PLC over USB or with an Ethernet device with an IP listed on the plc's host table once we are connected we can double we click on the ethernet port with the host table we want to disable this opens the same standard settings screen and we can navigate to the security setting tab if we uncheck the box for enable host table and click okay we can write the project to the CPU and it will now accept access from any IP address via Ethernet the host table is a great feature for network security applications where IP limiting is a necessity it is important to take care to add all needed IP addresses if we end up locking ourselves out of programming via Ethernet the only way to recover is to connect to the PLC with an allowed IP or to physically connect a USB cable to the front of the CPU