Difference Between Firewall and Router

Both Firewalls and Routers are devices that are connected to networks and pass through network traffic depending on some set of rules. A device or set of devices intended to allow permission to accept/deny transmissions based on a certain set of rules is called a firewall. Firewall is used to protect networks from unauthorized access, while permitting legitimate transmissions to go through. On the other hand, a router is a device used to forward packets between two networks and act as an intermediate node that connects two networks.

What is a Firewall?

A Firewall is an entity (a device or a group of devices) designed to control (permit or deny) network traffic using a set of rules. A Firewall is designed to permit only the authorized communications to pass through it. A Firewall can be implemented in both hardware and software. Software-based firewalls are a common place in many personal computer operating systems. Moreover, firewall components are contained in many routers. Conversely, many firewalls can perform functionality of routers as well.

There are several types of firewalls. They are classified based on the location of communication, location of interception and state being traced. A Packet filter (also known as network layer firewall), as the name suggests, looks at packets entering or leaving the network and accepts or rejects based on the filtering rules. Firewalls that apply security mechanisms to specific applications, such as FTP and Telnet servers are called Application gateway proxies. In theory, that Application level firewall is able to prevent all unwanted traffic. Circuit-level gateway applies security mechanisms when UDP/TCP is used. A Proxy server itself can be used as a Firewall. Since it can intercept all messages entering and leaving the network, it can effectively hide the true network address.

What is a Router?

A router is a device used to forward packets between two networks (usually between a LAN and a WAN or LAN and an ISP). It helps to create an overlay internetwork. A router usually holds a routing table (or a routing policy). When a packet arrives from one of the networks it is connected to, it will first check the address information inside the packet to find out the destination. Then, depending on the routing table (or policy) it will either forward to the other network or simply drop the packet. A packet is forwarded from router to router until it reaches its destinations.

What is the difference between Firewall and Router?

So, it is clear that both Firewalls and Routers are seemingly similar because they both pass the network traffic through them, but they do have their differences. The actual duty of a router is transporting data between networks, while a firewall is dedicated to screen data going across a network. Typically routers stay in between multiple networks, whereas a firewall will stay inside a designated computer and stop unauthorized requests from reaching non-public resources. Router can be identified as a device that directs traffic, while a Firewall is installed mainly for protection or security purposes.