Step 5: Add a Security Group Rule

Scenarios

A security group consists of inbound and outbound rules to control the traffic that is allowed to flow into or out of instances (such as ECSs) in the security group. Security group rules are commonly used to allow or deny network traffic from specific sources or over specific protocols, block certain ports, and define specific access permissions for instances.

Adding Rules to a Security Group

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

   The VPC list page is displayed.

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

   The security group list is displayed.

4. Locate the target security group and click Manage Rules in the Operation column.

   The page for configuring security group rules is displayed.

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

   The Add Inbound Rule dialog box is displayed.

6. Configure required parameters.

   You can click + to add more inbound rules.

   Table 1 Inbound rule parameter description

   Parameter	Description	Example Value
   Type	Source IP address version. You can select: IPv4 IPv6	IPv4
   Protocol & Port	The network protocol used to match traffic in a security group rule. The protocol can be All, TCP, UDP, GRE, or ICMP.	TCP
   	Destination port used to match traffic in a security group rule. The value can be from 1 to 65535. Inbound rules control incoming traffic over specific ports to instances in the security group.	22, 22-30
   Source	Source of the security group rule. The value can be IP address or Security group, to allow access from the IP addresses or the instances in the security group. If you select IP address for Source, you can enter multiple IP addresses in the IP address box. Each IP address represents a different security group rule. 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 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	(Optional) Supplementary information about the security group rule. The description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	-

7. Click OK.

   The inbound rule list is displayed.

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

   The Add Outbound Rule dialog box is displayed.

9. Configure required parameters.

   You can click + to add more outbound rules.

   Table 2 Outbound rule parameter description

   Parameter	Description	Example Value
   Type	Destination IP address version. You can select: IPv4 IPv6	IPv4
   Protocol & Port	The network protocol used to match traffic in a security group rule. The protocol can be All, TCP, UDP, GRE, or ICMP.	TCP
   	Destination port used to match traffic in a security group rule. The value can be from 1 to 65535. Outbound rules control outgoing traffic over specific ports from instances in the security group.	22, 22-30
   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. If you select IP address for Destination, you can enter multiple IP addresses in the same IP address box. Each IP address represents a different security group rule. 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	0.0.0.0/0
   Description	(Optional) Supplementary information about the security group rule. The description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	-

10. Click OK.

    The outbound rule list is displayed and you can view your added rule.

Checking Whether a Port Is Enabled on an ECS

After allowing traffic over a port in a security group rule, you need to ensure that the port used by the instance is also opened.