# Adding Security Group Rules

#### Scenarios

The default security group rule allows all outgoing data packets. BMSs in a security group can access each other without the need to add access rules. After a security group is created, you can create different access rules for the security group to protect the BMSs that are added to this security group.

You can add only one security group when creating a BMS. After the BMS is created, you can modify the security group of each NIC on the BMS details page.

#### Suggestions

- When adding a security group rule for a BMS, grant the minimum permissions possible:
  - Enable specific ports rather than a port range, for example, port 80.
  - Be cautious to authorize source address 0.0.0.0/0 (entire network segment).
- You are not advised to use one security group to manage all applications because isolation requirements for different layers vary.
- Configuring a security group for each BMS is unnecessary. Instead, you can add BMSs with the same security protection requirements to the same security group.
- Simple security group rules are recommended. For example, if you add a BMS to multiple security groups, the BMS may comply with hundreds of security group rules, and a change to any rule may cause network disconnection for the BMS.

#### Procedure

1. Log in to the management console.
2. Under Computing, click Bare Metal Server.

   The BMS console is displayed.

3. In the BMS list, click the name of the BMS whose security group rules you want to modify.

   The page showing details of the BMS is displayed.

4. Click the Security Groups tab and then to view security group rules.
5. Click the security group ID.

   The system automatically switches to the Security Group page.

6. Click Manage Rule in the Operation column. On the security group details page, add a rule.

   Value Inbound indicates that traffic enters the security group, and value Outbound indicates that traffic leaves the security group.

   Table 1 Parameter description
   Parameter | Description
   --- | ---
   Protocol | Specifies the network protocol for which the security group rule takes effect. The value can be TCP, UDP, ICMP, HTTP, or others.
   Port | Specifies the port or port range for which the security group rule takes effect. The value ranges from 0 to 65535.
   Source | Specifies the traffic source (inbound rule). This parameter is required for an inbound rule. The value can be an IP address or a security group.
   Destination | Specifies the traffic destination (outbound rule). This parameter is required for an outbound rule. The value can be an IP address or a security group.

   The default source IP address 0.0.0.0/0 indicates that all IP addresses can access BMSs in the security group.

Parent topic: Security Group