Bringing up an interface without an IP address
To create a network interface without an IP address at all use the manual method and use pre-up and post-down commands to bring the interface up and down.
This can be necessary, when you like to bridge a VMWare VM to this interface or when it’s connected to a mirror port on the switch for sniffing purposes.
Add an entry like this in your /etc/network/interfaces file:
iface eth0 inet manual pre-up ifconfig $IFACE up post-down ifconfig $IFACE down
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