Debian - How to configure an interface as promisc

In order to configure your interface you will need to edit the following file, /etc/network/interfaces
Below is an example of this file, this would set eth0 an IP ( and eth1 and eth2 to promisc mode.

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
        # dns-* options are implemented by the resolvconf package, if installed

auto eth1
iface eth1 inet manual
        up ifconfig eth1 promisc up
        down ifconfig eth1 promisc down

auto eth2
iface eth2 inet manual
        up ifconfig eth2 promisc up
        down ifconfig eth2 promisc down

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R Donato

Ricky Donato is the Founder and Chief Editor of He currently works as a Principal Network Security Engineer and has a keen interest in automation and the cloud.

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