Can a firewall be used as a router?

This is one very important question asked by business owners, especially when they don’t wish to invest in both network firewall security and a router. They expect network firewall security to do everything and eliminate the cost of a router. But they don’t get the expected response. People are doubtful if it’s possible.

In this post, we will try to clear this confusion. But, before that, we will discuss what a firewall and a router are and the differences between them.

Router: As the connecting device in networking, a router is used to select the shortest route for a packet to achieve its target. The main purpose of a router is to attach different networks simultaneously.

Similar to a firewall, a router works on the network layer. However, it works on the physical layer as well as the data link layer of the Open System Interconnection (OSI) model. The difference is that a router doesn’t include encryption before routing the networks as a firewall does.

A major role of a router is that it shares the provision to share internet connection between the networks but doesn’t protect the network from threats.

Firewall: As a specified version of the router, a firewall monitors traffic and blocks unauthorized attempts to enter the network, while a router simply passes traffic between two separate networks. In simple terms, a firewall acts as a network security appliance and should be robust wherever it is used. It sits between two networks, enforcing an access control policy.

Like a router, a firewall operates at the network layer of the Open System Interconnection (OSI) model. However, a firewall uses encryption to secure data before transmission, unlike a router.

A firewall’s primary role is to protect the network from threats, but it does not share the network.

Differences between a firewall and a router

A firewall checks incoming packets for threats, while a router connects various networks simultaneously. A firewall operates at the network and transport layers of the OSI model, whereas a router functions at the physical, network, and data link layers.

Firewalls encrypt data before transmission, while routers do not use encryption. Unlike firewalls, which cannot share a network, routers share an internet connection among networks. A firewall may exist within a router, but a router does not exist within a firewall.

Firewalls filter and regulate data, while routers manage traffic to its intended destination. Firewalls maintain a state table that provides information on data flow, while routers do not keep a state table for flow information. Generally, a firewall protects the core network of a computer, whereas routers handle routing and terminating WAN links.

As you can see, many differences exist between firewalls and routers. However, you will find some similarities upon closer examination. For example, both operate within the Open System Interconnection model, and a firewall can exist inside a router. Considering these points, we can say that a firewall can function as a router, with differences mainly in implementation and functionality.

Another way to explain that a firewall can be used as a router

A router uses network address translation (NAT) to share a single IP address from the internet service provider among multiple computers. When incoming traffic from the internet reaches the router, it may discard the traffic if it doesn’t know which computer to forward it to.

In this case, NAT acts as a firewall, blocking unwanted incoming requests from reaching the computers. Depending on the router’s type, you can also block specific outgoing traffic by adjusting the settings. You can allow the router to forward some traffic by setting up port forwarding or placing a computer in a demilitarized zone (DMZ), but this means that the computer will lose the firewall protection provided by the router.

Since a firewall can perform the functions of a router, it can serve as a replacement. A firewall can manage routing responsibilities while also providing additional security features.

Other functions of a firewall 

A firewall sits between a network and a computer. It analyzes all traffic that reaches or leaves the network, deciding how to handle it. The firewall blocks unsolicited incoming traffic and can also be configured to block specific types of outgoing traffic or log suspicious activity.

Firewalls operate based on a set of rules. For instance, they might allow connections to a server from a specific IP address while denying connection requests from other sources to enhance security.

When configuring a firewall, administrators can permit web browsing traffic while blocking access to other applications.

Firewalls offer numerous benefits for organizations. They also save money by serving as a router in many situations.

Author: TechBlonHub

As a passionate blogger, I'm thrilled to share my expertise, insights, and enthusiasm with you. I believe that technical knowledge should be shared, not hoarded. That's why I take the time to craft detailed, well-researched content that's easy to follow, even for non-tech. I love hearing from you, answering your questions, and learning from your experiences. Your feedback helps me create content that's tailored to your needs and interests