What are security groups and how do I use them?

The concept of security groups is used to prevent unwanted and malicious network traffic from or to the machines. It can be seen as an external (outside of the VM itself) firewall that can be fully configured by the user.

It is worth noting that the default security group does not even allow incoming SSH connections! If you want to access your VMs via SSH you need to add a corresponding rule to the security group you want to use first.

If you run into problems regarding network connectivity of your VMs security groups are a good place to start debugging your problems.

Please note: you can modify the Security Groups any time. The changes take effect immediately. You do not need to restart or shelve and unshelve your VM.