Configuring Security Group Rules for a FlexusL Instance

Scenarios

A security group is a collection of access control rules and consists of inbound and outbound rules. You can add security group rules to allow or deny the traffic to reach and leave the FlexusL instances in the security group.

Security group rules allow or deny network traffic from specific sources over specific protocols or specific ports.

For details about configuration examples, see Security Group Examples.
For details about how to configure security group rules for FlexusL application images, see Configuring Security Groups for FlexusL Application Images.

Precautions

Before configuring security group rules, you need to plan rules for communications among instances in the security group.
Add as fewer rules as possible. For details about the constraints on the number of rules in a security group, see Notes and Constraints.
After allowing traffic over a port in a security group rule, ensure that the port is opened in the instance. For details, see Verifying Security Group Rules.
Generally, all FlexusL instances created by the same account in the same region are in the same security group and they can communicate with each other by default.

Procedure

Log in to the FlexusL console and click a resource card to go to the instance details page.
In the navigation pane on the left, choose Cloud Servers and then click the server name.
Select Inbound rules from the Security Group drop-down list and click Add Rule on the Security Groups tab.
You can click + to add more inbound rules. For details about the parameters, see Adding a Security Group Rule.

Figure 1 Adding an inbound rule
Select Outbound rules from the Security Group drop-down list and click Add Rule on the Security Groups tab.
You can click + to add more outbound rules. For details about the parameters, see Adding a Security Group Rule.
Click OK.
After allowing traffic over a port in a security group rule, ensure that the port is opened in the instance. For details, see Verifying Security Group Rules.

Related Operations

On the Inbound Rules and Outbound Rules tab pages, you can also modify, replicate, or delete existing rules.

Deleting security group rules will disable some functions.

If you delete a rule with Protocol & Port specified as TCP: 20-21, you will not be able to upload files to or download them from servers using FTP.
If you delete a rule with Protocol & Port specified as ICMP: All, you will not be able to ping the servers.
If you delete a rule with Protocol & Port specified as TCP: 443, you will not be able to connect to websites on the servers using HTTPS.
If you delete a rule with Protocol & Port specified as TCP: 80, you will not be able to connect to websites on servers using HTTP.
If you delete a rule with Protocol & Port specified as TCP: 22, you will not be able to remotely connect to Linux server using SSH.