Below is a very light virtual machine based on Core Linux kernel 4.8 (TinyCore) 26 Mo with network tools like iperf3, tcpdump, net-bridging, iproute2, busybox (httpd), tcpreplay, nmap, openssh.
basic commands/directory
/etc/sysconfig/tcedir/optional => packages
/etc/sysconfig/tcedir/onboot.lst => on boot package to be loaded
sudo vi /opt/eth0.sh => change interfaces parameters
#configure an interface
pkill udhcp => stop dhcp for this interface
ifconfig eth0 10.253.106.2 netmask 255.255.255.192 up
route add default gw 10.253.106.1
filetool.sh -b => save the configuration changes
vi /opt/hostnameAuto.sh => change the hostname
vi /opt/bootlocal.sh => the script that is executed after the device has booted.