How can I set the NIC to promiscous mode ?

Products

• Data Loss Prevention Network Monitor

Issue/Introduction

How can a NIC be set into promiscous mode ? 

Resolution

On Windows:

It depends on the card.  You may want to check the advanced properties for your network card.

You can also de-select all protocols for the NIC.
You may also be able to configure this in the registry. For many cards this can be set in the HKey_LocalMachine\SYSTEM\CurrentControlSet\Services\NIC_CARD\Parameters (where NIC_CARD is your nic driver) -

 

Value Name: PromiscuousModeX

Data Type: REG_DWORD

Data: 1

Data 1 will enable the mode.

On Linux:

You can use ifconfig as in the following example.

To put the NIC in promiscuous mode:

[root]# ifconfig eth0 promisc

To remove the NIC from promiscuous mode:

[root]# ifconfig eth0 -promisc

On machines running under VMware ESX:

You may need to change the configuration of the virtual switch on which you want to run packet capture. By default, VMware ESX will not allow guest virtual machines to set their network ports to promiscuous mode.

In VMware ESX Server 3.5, you can find this option in the VMware Infrastructure Client under each host machine, under Configuration > Networking > Virtual Switch > Properties.