Setup

• Download VirtualBox
• Download Ubuntu Server: https://ubuntu.com/download/server
• Setup initial virtual machine

• To change network name to "eth0" for convenience, first to get the interface's information, use ip a

• From the dmesg command, you can see that the device got renamed during the system boot

dmesg | grep -i eth

• To get an ethX back, edit the grub file:

sudo nano /etc/default/grub

Enter your password, look for "GRUB_CMDLINE_LINUX" then change

From:

GRUB_CMDLINE_LINUX=""

Change to:

GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"

Note: save file

• Finally, edit the interface file in /etc/netplan (using cd /, then cd etc/netplan/ and ls to get filename 00-network-manager-all.yaml) and change the network device name so that you will have a DHCP or static IP address for eth0, eth1 and eth2 (using sudo nano 00-network-manager-all.yaml)

Reboot device after changing

The result is:

Configure 6 interfaces by the command

• Flush the device before bringing it up

sudo ip addr flush dev eth0

• You should clone virtual machine to 4 VMs, choose Generate new MAC addresses for all network adapters
• Configure 6 interfaces by the command:

PCA: sudo ip -6 addr add 2001:2::10/64 dev eth1
PCB: sudo ip -6 addr add 2001:3::10/64 dev eth1
Router1: sudo ip -4 addr add 129.175.1.1 dev eth2
         sudo ip -6 addr add 2001:2::1/64 dev eth1
Router2: sudo ip -4 addr add 129.175.1.2 dev eth2
         sudo ip -6 addr add 2001:3::1/64 dev ethl

where -6 represents the ipv6 network, eth0 is the device's name and 2001:2::/64 is the inet6 prefix.

Activate devices (both Router1 and Router2)

sudo ip link set eth1 up
sudo ip link set eth2 up

Enable forwarding:

cd /
cd etc/
sudo nano sysctl.conf

Uncomment net.ipv4.ip_forward=1 by delete # before that line

Configure the tunnel between the two border routers

Write the command line to add the remote of IPv4 address to the tunnel in order to create a IPv6-in-IPv4 tunnel

• Router1: $ sudo ip tunnel add tunnell mode sit remote 129.175.1.2 local 129.175.1.1 ttl 255
• Router2: $ sudo ip tunnel add tunnell mode sit remote 129.175.1.1 local 129.175.1.2 ttl 255

To activate the tunnel, we use the command:

ip link set tunnell up

When finish, the tunnel will be show as an interface in ifconfig

• To add ipv6 address to the tunnel, use sudo ip addr add 2001:2::/64 dev tunnell

Configure routing tables on all PCs

To flush all routes on the routing tables, the ip command options route flush table main are used. The full commands to run are:

sudo ip route flush table main
ip route show

Observe with Wireshark

For Router1 or Router2

sudo apt install tshark
sudo tshark -i eth1

The results are: