Adding virtual interfaces (not VLAN) in linux

Question

for some software testing, I need 12 different IP addresses to contact, each one with a unique MAC address. I just set up an Arch Linux VM but I can't figure out, how to configure virtual network interfaces all pointing to the same (virtual) ethernet port.

Is this even possible?

Answer 1

You can do this through setting up ethernet bridge. You are effectively setting up a virtual switch/router, and add as many taps/ports as you desire.

I have had the following script setup for running a number of VM in a isolated network. Hope it can be useful to you:

USER=username
NUMBER_OF_VM=4
BR_NAME=vbr
IP_RANGE=10.1.1.1/24
IP_ROUTE=10.1.1.0/24

# Creates a new instance of the ethernet bridge
echo "Creating bridge: $BR_NAME"
brctl addbr $BR_NAME
# Activate the bridge
ip link set up dev $BR_NAME

# Create persistent TAPs and attach to bridge
echo "Creating $NUMBER_OF_VM tap(s) to attach to the $BR_NAME bridge"
NB=0
while [ $NB -lt $NUMBER_OF_VM ]
do
   tunctl -t vbxtap$NB -u $USER
   ip link set up dev vbxtap$NB
   brctl addif $BR_NAME vbxtap$NB
   let NB=$NB+1
done

# Assign ip address and routing to the bridge interface
echo "Assign $IP_RANGE to $BR_NAME"
ip addr add $IP_RANGE dev $BR_NAME
#echo "Assign routing rule $IP_ROUTE to $BR_NAME"
#ip route add $IP_ROUTE dev $BR_NAME