Step 5: Add a Security Group Rule

Scenarios

A security group is a collection of access control rules to control the traffic that is allowed to reach and leave the cloud resources that it is associated with. The cloud resources can be cloud servers, containers, databases, and more. Cloud resources associated with the same security group have the same security requirements and are mutually trusted within a VPC. A security group consists of inbound and outbound rules.

Each ECS must be associated with at least one security group. If you do not have a security group when creating an ECS, the system provides a default security group.

If the rules of the security group associated with your instance cannot meet your requirements, for example, you need to allow inbound traffic on a specific TCP port, you can add an inbound rule to allow traffic on the TCP port.

Procedure

1. Log in to the management console.
2. Click in the upper left corner and select the desired region and project.
3. Click in the upper left corner and choose Network > Virtual Private Cloud.

   The Virtual Private Cloud page is displayed.

4. In the navigation pane on the left, choose Access Control > Security Groups.

   The security group list is displayed.

5. Locate the row that contains the target security group and click Manage Rules in the Operation column.

   The page for configuring security group rules is displayed.

6. On the Inbound Rules tab, click Add Rule.

   The Add Inbound Rule dialog box is displayed.

7. Configure required parameters.

   You can click + to add more inbound rules.

   Figure 1 Add Inbound Rule
   

   Table 1 Inbound rule parameter description

   Parameter	Description	Example Value
   Protocol	The network protocol used to match traffic in a security group rule. Currently, the value can be All, TCP, UDP, GRE, ICMP, or more.	TCP
   Port	The port or port range over which traffic can reach your ECS. The value can be from 1 to 65535.	22, or 22-30
   Type	Source IP address version. You can select: IPv4 IPv6	IPv4
   Source	Source of the security group rule. The value can be an IP address or a security group to allow access from IP addresses or instances in the security group. IP address: Single IP address: 192.168.10.10/32 All IP addresses: 0.0.0.0/0 IP address range: 192.168.1.0/24 Security group: The source is from another security group. You can select a security group in the same region from the drop-down list. If there is instance A in security group A and instance B in security group B, and the inbound rule of security group A allows traffic from security group B, traffic is allowed from instance B to instance A. If the source is a security group, this rule will apply to all instances associated with the selected security group.	0.0.0.0/0
   Description	Supplementary information about the security group rule. This parameter is optional. The security group rule description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	N/A

8. Click OK.

   The inbound rule list is displayed.

9. On the Outbound Rules tab, click Add Rule.

   The Add Outbound Rule dialog box is displayed.

10. Configure required parameters.

    You can click + to add more outbound rules.

    Figure 2 Add Outbound Rule
    

    Table 2 Outbound rule parameter description

    Parameter	Description	Example Value
    Protocol	The network protocol used to match traffic in a security group rule. Currently, the value can be All, TCP, UDP, GRE, ICMP, or more.	TCP
    Port	The port or port range over which traffic can leave your ECS. The value can be from 1 to 65535.	22, or 22-30
    Type	Source IP address version. You can select: IPv4 IPv6	IPv4
    Destination	Destination of the security group rule. The value can be an IP address or a security group to allow access to IP addresses or instances in the security group. IP address: Single IP address: 192.168.10.10/32 All IP addresses: 0.0.0.0/0 IP address range: 192.168.1.0/24 Security group: The source is from another security group. You can select a security group in the same region from the drop-down list. If there is instance A in security group A and instance B in security group B, and the inbound rule of security group A allows traffic from security group B, traffic is allowed from instance B to instance A.	0.0.0.0/0
    Description	Supplementary information about the security group rule. This parameter is optional. The security group rule description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	N/A

11. Click OK.

    The outbound rule list is displayed.