A security group is a collection of firewall rules. By grouping these rules in a security group you can easily assign these groups to one or more virtual servers.
Which rules should I add?
Which rules to add to a security group differs per user case. There are a few rules that are needed for most virtual servers. We advise you to create a security group for these rules, so you can easily assign these rules to all of your virtual servers.
Some rules that are needed for most virtual machines are:
- Port 22, for SSH
- Port 53, for DNS