Configuring the Promiscuous Mode on NI Linux Real-Time Controllers

This article explains how to enable or disable the promiscuous mode on NI Linux Real-Time (RT) controllers. The promiscuous mode refers to a setting on a network interface card (NIC) that allows the interface to receive and process all ethernet frames it sees on the network, not just the packets specifically addressed to its own MAC address. 

To execute the process below, ensure you have access to a host PC with the correct firewall configuration to allow communication with the RT controller.  

1. Access the shell on the RT controller
2. List all the available network interfaces to get the name of the one you are looking to configure, by running the following command:

ip link

3. Enable or disable the promiscuous mode using one of the commands below, correspondingly:

# To disable the promiscuous mode
ip link set <name_of_NIC> promisc off


#To enable the promiscuous mode
ip link set <name_of_NIC> promisc on

After configuring the promiscuous mode on the RT controller, you can check whether it is enabled or disabled by running the following command:

ip link show <name_of_NIC> | grep PROMISC

If the promiscuous mode is enabled, the above command will generate the response below:

If it is disabled, no response will be displayed.