What is a cloud firewall? What is firewall-as-a-service (FWaaS)?

A cloud firewall protects cloud infrastructure from attacks, just as a traditional firewall protects on-premise networks.

Learning Objectives

After reading this article you will be able to:

  • Understand what a cloud firewall is
  • Understand what 'Firewall-as-a-Service' means
  • Explore how cloud computing changes the network perimeter

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What is a cloud firewall?

A cloud firewall is a security product that, like a traditional firewall, filters out potentially malicious network traffic. Unlike traditional firewalls, cloud firewalls are hosted in the cloud. This cloud-delivered model for firewalls is also called firewall-as-a-service (FWaaS).

Cloud-based firewalls form a virtual barrier around cloud platforms, infrastructure, and applications, just as traditional firewalls form a barrier around an organization's internal network. Cloud firewalls can also protect on-premise infrastructure.

Cloud firewall blocks attacks at cloud deployments

Definition of a firewall

A firewall is a security product that filters out malicious traffic. Traditionally, firewalls have run in between a trusted internal network and an untrusted network – e.g., between a private network and the Internet. Early firewalls were physical appliances that connected to an organization's on-premise infrastructure. Firewalls block and allow network traffic according to an internal set of rules. Most firewalls allow administrators to customize these rules.

traditional firewall

The border between a trusted network and the Internet is called the "network perimeter." However, with the growing popularity of cloud computing, the network perimeter is mostly gone. Thus, cloud firewalls that form a virtual barrier between trusted cloud assets and untrusted Internet traffic are increasingly important.

Is firewall-as-a-service (FWaaS) different from cloud firewalls?

Firewall-as-a-Service, or FWaaS for short, is another term for cloud firewalls. Like other "as-a-service" categories, such as software-as-a-service (SaaS) or infrastructure-as-a-service (IaaS), FWaaS runs in the cloud and is accessed over the Internet, and a third-party vendor updates and maintains it.

Why use FWaaS?

Banks have a lot of physical security in place. Most brick-and-mortar banks will include security features like security cameras and bulletproof glass. Security guards and bank employees also help stop potential thieves, and cash is stored in highly secure safes.

But imagine if, instead of being kept in one place, each bank branch's cash was stored in different safes all over the country that were operated by a company specializing in safe maintenance. How could the bank be sure that its money was secure without deploying additional security resources around its scattered safes? This is akin to what cloud firewalls do.

The cloud is like a bank with scattered resources, but instead of money, the cloud stores data and computational power. Authorized users can connect to the cloud from anywhere and on almost any network. Applications that run in the cloud can be running anywhere, and that also applies to cloud platforms and infrastructure.

Cloud firewalls block cyber attacks directed at these cloud assets. Deploying a cloud firewall is like replacing a bank's local security cameras and a physical security guard with a global 24/7 security center that has a centralized staff and security camera feeds from all the places where a bank's assets are stored.

What are the main benefits of using a cloud firewall/FWaaS?

  • Malicious web traffic is blocked, including malware and bad bot activity. Some FWaaS products can also block sensitive data from going out.
  • Traffic does not have to be funneled through a hardware appliance, so no network choke points are created.
  • Cloud firewalls integrate easily with cloud infrastructure.
  • Multiple cloud deployments can be protected at once (as long as the cloud firewall vendor supports each cloud).
  • Cloud firewalls scale up rapidly to handle more traffic.
  • Organizations do not need to maintain cloud firewalls themselves; the vendor handles all updates.

What is the difference between a cloud firewall and a next-generation firewall (NGFW)?

A next-generation firewall (NGFW) is a firewall that includes new technologies that weren't available in earlier firewall products, such as:

  • Intrusion prevention system (IPS): An intrusion prevention system detects and blocks cyber attacks.
  • Deep packet inspection (DPI): NGFWs inspect data packet headers and payload, instead of just the headers. This aids in detecting malware and other kinds of malicious data.
  • Application control: NGFWs can control what individual applications can access, or block applications altogether.

NGFWs can run in the cloud or as on-premise hardware. A cloud-based firewall may have NGFW capabilities, but an on-premise firewall could also be an NGFW. Learn more about NGFW vs. FWaaS.

How does FWaaS fit into a SASE framework?

Secure access service edge, or SASE, is cloud-based networking architecture that combines networking functions, like software-defined WANs, with a set of security services, including FWaaS. Unlike traditional networking models, where the perimeter of on-premise data centers has to be protected with on-premise firewalls, SASE offers comprehensive security and access control at the network edge.

Within a SASE networking model, cloud-based firewalls work in tandem with other security products to defend the network perimeter from attacks, data breaches, and other cyber threats. Rather than using multiple third-party vendors to deploy and maintain each service, companies can use a single vendor that bundles FWaaS, cloud access security broker (CASB) services, secure web gateways (SWG), and zero trust network access (ZTNA) with SD-WAN capabilities.

Cloudflare Magic Firewall is designed to protect both on-premise and cloud infrastructure via the Cloudflare global network. Magic Firewall is included in the Cloudflare One SASE platform.

Businesses looking to protect their web applications can also use the Cloudflare WAF Learn more about Cloudflare's Web Application Firewall.