Security groups are used to manage traffic to and from public and private networks. For the sake of security, most inbound traffic is denied by default. If you selected Open all ports or Open ports 22, 80, 443, 3389 and ICMP protocol as the template when creating a security group, rules are automatically created and added to the security group to allow traffic on those ports. For more information, please see Security Groups.
This document describes how to add security group rules to allow or reject traffic to and from public or private networks.
- Security group rules support IPv4 and IPv6 rules.
- Open all ports allows both IPv4 and IPv6 traffic.
- You should have an existing security group. If you do not, refer to Creating a Security Group for details.
- You should know which traffic is allowed or rejected for your CVM instance. For more information on security group rules and their use cases, please see Security Group Use Cases.
- Log in to the CVM console.
- Select Security Group on the left sidebar to access the security group management page.
- Select a region, and locate the security group for which you want to set rules.
- Click Modify Rules in the Operation column.
- Click Inbound rules and choose either of the following methods to add rules.
The following instructions use Add a Rule as an example.
- Open all ports: this method is ideal if you do not need custom ICMP rules and all traffic goes through ports 20, 21, 22, 80, 443, and 3389 and the ICMP protocol.
- Add a Rule: this method is ideal if you need to use multiple protocols and ports other than those mentioned above.
- In the pop-up window, set rules.
Configure the following parameters:
- Type: Custom is selected by default. You can also choose another system rule template including Login Windows CVMs (3389), Login Linux CVMs (22), Ping, HTTP (80), HTTPS (443), MySQL (3306), and SQL Server (1433).
- Source or Destination: traffic source (inbound rules) or destination (outbound rules). You need to specify one of the following options:
|Source or Destination||Description|
|A single IPv4 address or an IPv4 range||In CIDR notation, such as |
0.0.0.0/0 indicates all IPv4 addresses will be matched.
|A single IPv6 address or an IPv6 range||In CIDR notation, such as |
0::0/0 indicates all IPv6 addresses will be matched.
|ID of the referenced security group. You can reference the ID of:|
- Current security group
- Other security group
- To reference the current security group, please enter the ID of security group associated with the CVM.
- You can also reference another security group in the same region and belongs to the same project by entering the security group ID.
- The referenced security group is available to you as an advanced feature. The rules of the referenced security group are not added to the current security group.
- If you enter the security group ID in **Source**/**Destination** when configuring security group rules, the private IP addresses of the CVM instances and the ENIs that are associated with this security group ID are used as the source/destination. This does not include public IP addresses.
|Reference an IP address object or IP address group object in a parameter template.||-|
- Protocol port: enter the protocol type and port range or reference a protocol/port or protocol/port group in a parameter template. The supported protocol type includes TCP, UDP, ICMP, ICMPv6 and GRE in the following formats.
- Single port: such as
- Multiple ports: such as
- Port range: such as
- All ports: such as
- Policy: Allow or Refuse. Allow is selected by default.
- Allow: traffic to this port is allowed.
- Refuse: data packets will be discarded without any response.
- Notes: a short description of the rule for easier management.
- Click Complete to finish adding the rule.
- To add an outbound rule, click Outbound rule and refer to Step 5 to Step 7.