Google Cloud Armor overview

Google Cloud Armor helps you protect your Google Cloud deployments from multiple types of threats, including distributed denial-of-service (DDoS) attacks and application attacks like cross-site scripting (XSS) and SQL injection (SQLi). Google Cloud Armor features some automatic protections and some that you need to configure manually. This document provides a high-level overview of these features.

Security policies

Use Google Cloud Armor security policies to protect applications running behind a load balancer from distributed denial-of-service (DDoS) and other web-based attacks, whether the applications are deployed on Google Cloud, in a hybrid deployment, or in a multi-cloud architecture. Security policies can be configured manually, with configurable match conditions and actions in a security policy. Google Cloud Armor also features preconfigured security policies, which cover a variety of use cases. For more information, see Google Cloud Armor security policy overview.

Rules language

Google Cloud Armor enables you to define prioritized rules with configurable match conditions and actions in a security policy. A rule takes effect, meaning that the configured action is applied, if the rule is the highest priority rule whose attributes match the attributes of the incoming request. For more information, see Google Cloud Armor custom rules language reference.

Preconfigured WAF rules

Google Cloud Armor preconfigured rules help protect your web applications and services from common attacks from the internet and help mitigate the OWASP Top 10 risks. The rules allow Google Cloud Armor to evaluate distinct traffic signatures by referring to conveniently-named rules, rather than requiring you to define each signature manually. The rule source is ModSecurity Core Rule Set 3.0.2 (CRS).

These preconfigured rules can be tuned to disable noisy or otherwise unnecessary signatures. For more information, see Tuning Google Cloud Armor WAF rules.

Named IP lists

Google Cloud Armor named IP address lists let you reference lists of IP addresses and IP ranges that are maintained by third-party providers. You can configure named IP address lists within a security policy. You do not have to manually specify each IP address or IP range individually. For more information, see Named IP lists.

Google Cloud Armor Managed Protection

Managed Protection is the managed application protection service that helps protect your web applications and services from distributed denial-of-service (DDoS) attacks and other threats from the internet. Managed Protection features always-on protections for your load balancer, and gives you access to WAF rules.

DDoS protection is automatically provided for HTTP(S) Load Balancing, SSL Proxy Load Balancing, and TCP Proxy Load Balancing, regardless of tier. The HTTP, HTTPS, HTTP/2, and QUIC protocols are all supported.

For more information, see Managed Protection overview.

Google Cloud Armor Adaptive Protection

Adaptive Protection helps you protect your applications and services from L7 distributed denial-of-service (DDoS) attacks by analyzing patterns of traffic to your backend services, detecting and alerting on suspected attacks, and generating suggested WAF rules to mitigate such attacks. These rules can be tuned to meet your needs. Adaptive Protection can be enabled on a per- security policy basis, but it requires an active Managed Protection subscription in the project.

For more information, see Google Cloud Armor Adaptive Protection overview.

How Google Cloud Armor works

Google Cloud Armor provides always-on DDoS protection against network or protocol-based volumetric DDoS attacks for applications or services behind external HTTP(S) load balancers, SSL proxy load balancers, or TCP proxy load balancers. Google Cloud Armor's DDoS protection is always-on inline, scaling to the capacity of Google's global network. It is able to instantly detect and mitigate network attacks in order to allow only well-formed requests through the load balancing proxies. Backend services behind an external HTTP(S) load balancer also have access to security policies to enforce custom Layer 7 filtering policies, including pre-configured WAF rules to mitigate the OWASP Top 10 web application vulnerability risks.

Google Cloud Armor security policies enable you to allow or deny access to your external HTTP(S) load balancer at the Google Cloud edge, as close as possible to the source of incoming traffic. This prevents unwelcome traffic from consuming resources or entering your Virtual Private Cloud (VPC) networks.

The following diagram illustrates the location of the external HTTP(S) load balancers, the Google network, and Google data centers.

Google Cloud Armor policy at network edge.
Google Cloud Armor policy at network edge (click to enlarge)

You can use some or all of these features to protect your application. You can use security policies to match against known conditions, create WAF rules to protect against common attacks like those found in the ModSecurity Core Rule Set 3.0.2, and use Google Cloud Armor Managed Protection's built-in protections against DDoS attacks.

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