Networking

Goal

In this project you'll create a database and learn how to connect to it.

Hints

Try to solve the following tasks on your own without using the hints.
If you get stuck, you'll find an expandable hint block for every task with a detailed description of the solution.

Preparation - Configure VSCode

In this hands-on, we will look at connecting two VMs with private networks. This is easiest if the ssh connection to the two VMs are open side by side in split terminal windows. To do this, open VSCode, open a terminal, and click Split Button . Your VSCode should look more or less like this:

Split View

Task 1 - Create the two VMs

Create a security group with the CLI

exo compute security-group add network-handson-sg
exo compute security-group rule add network-handson-sg --port 22 --network

Set a variable for your existing ssh key

SSH_KEY_NAME=<your ssh key name>

Create the two VMs with the CLI

exo compute instance create \
  --disk-size 10 \
  --instance-type standard.micro \
  --template "Linux Ubuntu 22.04 LTS 64-bit" \
  --security-group network-handson-sg --ssh-key "$SSH_KEY_NAME" network-handson-vm1

Wait for the first vm to be ready and then create the second one

exo compute instance create \
  --disk-size 10 \
  --instance-type standard.micro \
  --template "Linux Ubuntu 22.04 LTS 64-bit" \
  --security-group network-handson-sg --ssh-key "$SSH_KEY_NAME" network-handson-vm2

Task 2 - Connect the two VMs

Connect to the first VM in the left terminal

ssh ubuntu@<ip>

Connect to the second VM in the right terminal

ssh ubuntu@<ip>

Task 3 - Test initial network connection

In the left terminal, ping the second VM

ping -c 3 <ip>

The VMs can not reach each other yet. We know already how to open up the security groups to make this work, however, in this hands-on we will first use private networks.

Task 4 - Create a managed private network

Create a managed private network with the UI or the CLI connecting the two VMs that we just created

Hints

Go to the Exoscale UI
Click on Compute in the left sidebar
Click on Private Networks in the left sidebar
Click on Add
Select DE-FRA-1 as the zone
Give the network a name
Select Managed as the type
Leave the default ip configuration
Click on Create
Select the network that you just created
Click on Attach
Select the two VMs that we just created

Task 5 - Enable the private IPs

The VMs we are using are not configured to use DHCP. Therefore we need to enable it manually.

In both VMs, run

sudo su
dhclient eth1

Task 5 - Test the private network

In the right terminal run the following command to monitor all incoming icmp traffic

tcpdump -i eth1 icmp

In the left terminal, ping the second VM, use the private IP that was assigned in the managed private network

ping -c 3 <ip>

You should see the ping requests in the right terminal
Stop the tcpdump in the right terminal with Ctrl + C

Task 6 - Create an unmanaged private network

Create an unmanaged private network with the UI or the CLI connecting the two VMs

Hints

Go to the Exoscale UI
Click on Compute in the left sidebar
Click on Private Networks in the left sidebar
Click on Add
Select DE-FRA-1 as the zone
Give the network a name
Select Manual as the type
Click on Create
Select the network that you just created
Click on Attach
Select the two VMs that we just created

Task 7 - Configure IP addresses for the VMs

In both VMs, run

ip a

The VMs now have a third network interface. This interface is not configured yet.

In the left terminal run:

ip addr add 192.168.0.1/24 dev eth2
ip link set eth2 up

In the right terminal run:

ip addr add 192.168.0.2/24 dev eth2
ip link set eth2 up

Start the tcpdump in the right terminal again

tcpdump -i eth2 icmp

In the left terminal, ping the second VM

ping -c 3 192.168.0.2

You should see the ping requests in the right terminal
Stop the tcpdump in the right terminal with Ctrl + C

Task 8 - Open the security groups

Start the tcpdump in the right terminal again, this time for the eth0 interface

tcpdump -i eth0 icmp

In the left terminal, ping the second VM

ping -c 3 <ip>

This will not work yet, because the security groups are not open
Open the security groups for icmp traffic from all instances in the same security group

Hints

Go to the Exoscale UI
Click on Compute in the left sidebar
Click on Security Groups in the left sidebar
Click on the security group that you created in task 1
Click on Add Rule
Click on Add Custom Rule
Select ICMP as the protocol
Select Security Group as the source type
Select the security group that you created in task 1
Click on Create

In the left terminal, ping the second VM

ping -c 3 <ip>

You should now see the ping requests in the right terminal