Overview

Updated on 2025-02-25 GMT+08:00

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Security Group

A security group is a collection of access control rules for cloud resources, such as cloud servers, containers, and databases, that have the same security protection requirements and that are mutually trusted. After a security group is created, you can configure access rules that will apply to all cloud resources added to this security group.

For more information about security groups, see security groups.

NOTE:

A security group works only when the network communication is normal. If two FlexusX instances are in the same security group but in different VPCs, the instances cannot communicate with each other. To enable communications between the two instances, connect the two VPCs first. For details, see Connecting VPCs.

Security Group Rules

After a security group is created, you can add rules to it. A rule applies either to inbound traffic (ingress) or outbound traffic (egress). Any FlexusX instances added to the security group are protected by the rules of that group. For details about more configuration examples, see Security Group Examples.

You can create a custom security group or use the default one provided by the system. The default security group allows all outbound traffic and denies inbound traffic. FlexusX instances in a security group can communicate with each other without adding any rules.

**Table 1** Default security group rules
Direction	Action	Type	Protocol & Port	Source/Destination	Description
Inbound	Allow	IPv4	All	Source: default security group (default)	Allows instances in the security group to communicate with each other over IPv4 protocols.
Inbound	Allow	IPv6	All	Source: default security group (default)	Allows instances in the security group to communicate with each other over IPv6 protocols.
Outbound	Allow	IPv4	All	Destination: 0.0.0.0/0	Allows access from instances in the security group to any IPv4 address over any port.
Outbound	Allow	IPv6	All	Destination: ::/0	Allows access from instances in the security group to any IPv6 address over any port.

Security Group Constraints

By default, you can create up to 100 security groups in your cloud account.
By default, you can add up to 50 rules to a security group.
For better network performance, you are advised to associate no more than five security groups with a FlexusX instance or supplementary network interface.
You can add up to 20 instances to a security group at a time.
You can add up to 1,000 instances to a security group.

Parent Topic: Configuring the Security Group for a FlexusX Instance

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