What Is The Promiscuous Mode?
By default when a network card receives a packet, it checks whether the packet belongs to itself. If not, the interface card normally drops the packet. But in promiscuous mode, the card doesn’t drop the packet. Instead, it will accept all the packets which flows through the network card.
Some Network Interface Cards (NICs) may not allow network traffic after you create a Network Bridge. This is due to the inability of NIC to automatically enable Promiscuous Mode when creating a Network Bridge. Following are the steps to enable it manually.
1. In the Start Menu search bar type cmd and press SHIFT + CTRL + ENTER to launch with Elevated Privileges.
2. Enter the following command to know the ID of your NIC
netsh bridge show adapter
In this example we see will assume the NIC id is 1.
3. When you know the NIC ID enter the following command to enable the Promiscuous Mode, remember to add the relevant NIC ID,
netsh bridge set adapter 1 forcecompatmode=enable
4. The above step will enable the Promiscuous Mode. Enter the command we used in Step 2, Now the Force Compatibility Mode (Promiscuous Mode) will display “enabled”.
Promiscuous Mode is automatically enabled when Bridging is activated, but some NIC models have some issues which can be solved by enabling it manually.