Security Groups act as virtual firewalls for CVMs. Each CVM instance must associate with at least one security group. By default, each CVM instance has two templates (Open all ports and Open port 22, 80, 443, 3389 and ICMP protocol) for creating a default security group. For details, refer to Security Group Overview.
If the default security group does not meet your needs, you can create your own security group as instructed below.
|Open all ports||All ports are open. May present security issues.||-|
|Open port 22，80，443，3389 and ICMP protocol||Port 22, 80, 443 and 3389, and the ICMP protocol are open. All ports are open internally.||Suitable for instances with web services.|
|Custom||Creates a blank security group in which rules are added afterwards. For details on how to add rules, refer to this article.||-|