Which of the following can be used to control the inbound and outbound traffic of...

The correct mechanisms are security groups and network ACLs . A security group contains inbound and outbound access-control rules governing traffic to and from ECS instances associated with the group. Inbound rules regulate traffic entering an ECS, while outbound rules regulate traffic leaving it. Security groups therefore provide the instance-oriented access-control layer within a Huawei Cloud VPC.

Network ACLs operate at the subnet level . A network ACL is associated with one or more subnets and controls traffic entering and leaving those subnets. In the HCIA V3.5 networking architecture, network ACLs complement security groups and provide an additional layer of network protection. Huawei's VPC documentation explicitly presents security groups and network ACLs as complementary controls for comprehensive access management.

IPsec VPN does not serve this role. Its purpose is to establish encrypted network connectivity—for example, between VPCs or between Huawei Cloud and an external network. Fingerprint authentication is likewise not a VPC packet-filtering mechanism.

Therefore, only A and D directly provide inbound/outbound traffic-control functionality for ECS workloads.

Reference topics: VPC Access Control; Security Groups; Network ACLs; ECS Network Security.

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