Configuring Security Group Rules

Scenarios

Similar to firewall, a security group is a logical group used to control network access. You can define access rules for a security group to protect the ECSs that are added to this security group.

• Inbound: Inbound rules allow external network traffic to be sent to the ECSs in the security group.
• Outbound: Outbound rules allow network traffic from the ECSs in the security group to be sent out of the security group.

For details about the default security group rules, see Virtual Private Cloud User Guide. For details about configuration examples for security group rules, see Security Group Configuration Examples.

Procedure

1. Log in to the management console.
2. Under Computing, click Elastic Cloud Server.
3. On the Elastic Cloud Server page, click the name of the target ECS.

   The page providing details about the ECS is displayed.

4. Click the Security Groups tab, expand the information of the security group, and view security group rules.
5. Click the security group ID.

   The system automatically switches to the security group details page.

6. Configure required parameters.

   You can click to add more inbound rules.

   Table 1 Inbound rule parameter description

   Parameter	Description	Example Value
   Protocol & Port	The network protocol used to match traffic in a security group rule. The value can be All, TCP, UDP, GRE, and 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, or 22-30
   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. IPv4 address: xxx.xxx.xxx.xxx/32 Subnet: xxx.xxx.xxx.0/24 Any IP address: 0.0.0.0/0 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

7. Configure required parameters.

   You can click + to add more outbound rules.

   Table 2 Outbound rule parameter description

   Parameter	Description	Example Value
   Protocol/Application	The network protocol. Currently, the value can be All, TCP, UDP, ICMP, or more.	TCP
   Port & Destination	Port: The port or port range over which the traffic can leave your ECS. The value ranges from 1 to 65535.	22, or 22-30
   	Destination: The destination of the security group rule. The value can be a single IP address or a security group to allow access to IP addresses or instances in the security group. For example: xxx.xxx.xxx.xxx/32 (IPv4 address) xxx.xxx.xxx.0/24 (IP address range) 0.0.0.0/0 (all IP addresses) sg-abc (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 to complete the security rule configuration.