# How Does CSS Ensure Data and Service Security?

CSS uses network isolation, in addition to various host and data security measures.

- Network isolation

  The entire network is divided into two planes: service plane and management plane. The two planes are deployed and isolated physically to ensure the security of the service and management networks.

  - Service plane: This is the network plane of the cluster. It provides service channels for users and delivers data definitions, indexing, and search capabilities.
  - Management plane: This is the management console, where you manage CSS.
- Host security

  CSS provides the following security measures:

  - The VPC security group ensures the security of the hosts in a VPC.
  - Network access control lists (ACLs) allow you to control what data can enter or exit your network.
  - The internal security infrastructure (including the network firewall, intrusion detection system, and protection system) monitors all network traffic that enters or exits the VPC through an IPsec VPN.
- Data security

  Multiple replicas, cross-AZ deployment of clusters, and third-party (OBS) backup of index data ensure the security of user data.

Parent topic: FAQs