Firewalls have been the first line of defense in network security for nearly 30 years.
A firewall is a network security device that monitors incoming and outgoing traffic and decides whether to block or allow that traffic based on specific security rules.
Firewalls establish a barrier between secured internal networks and untrusted outside networks, like the Internet.
In this blog, we are going to go into detail about how firewalls work, some different types, and how to pick the best one for your business.
How Do Firewalls Work?
A firewall can be computer hardware or software that can help protect your business network by filtering traffic and blocking hackers from gaining access to private data. Firewalls can also help block malware from infecting business machines.
A firewall will only work as it is configured to. A firewalled system analyzes network traffic based on rules; a firewall only allows those incoming connections that it has been configured to accept.
It is best to think of a firewall as the traffic guard at a business computer’s entry point, or port. Only trusted sources, or IP addresses, are allowed in.
Operating systems and security software usually comes with a pre-installed firewall. By default, most of these features are turned on, but they can be configured based on your team’s needs.
Firewalls also perform basic network functions such as Network Address Translation (NAT) and Virtual Private Network (VPN). Network Address Translation hides or “translates” private IP addresses to a public IP address. NAT is important because hiding IP addresses is a great way to defend businesses from their network being snooped on by hackers.
Similarly, a VPN extends a private network across a public network within a tunnel that is encrypted where the contents of the packets are protected while using the Internet. This allows employees to safely send and receive data across a home or public Wi-Fi.
A hardware firewall is physical, like a broadband router – your IT team would most likely install it on a rack with other network switches. A software firewall is internal – a program on a computer that works through several ports and applications.
There are also cloud-based firewalls. The biggest benefit of a cloud firewall is that it can grow with a business, scaling as the needs arise.
Firewall types differ by structure and functionality. Businesses can choose to implement whichever one fits their business needs, depending on the size of the network and the level of security.
A packet-filtering firewall is a program that can block network traffic IP protocol, an IP address, and a port number. This type of firewall is the most basic form of security and is meant for businesses with smaller networks.
Packet filtering firewalls are very fast in scanning traffic and inexpensive. They take up a small amount of space and have little effect on other resources, network performance, and employee experience.
Proxy service firewalls are systems that can help protect business networks by filtering messages. They serve as the middleman between a business network and outside servers on the Internet.
Next-generation firewalls (NGFW) are more advanced than packet-filtering and proxy service firewalls. NGFW includes deep packet inspection. While basic firewalls only look at packet headers, deep packet inspection looks at the data within the packet itself. NGFW can block more sophisticated and evolving security threats like advanced malware.
How Do I Pick a Firewall for My Business?
When choosing the right firewall for your team, you and your IT team should be mindful of a few things.
You should be mindful of the size of your staff. A high-end firewall for a simple office network of five people may not be necessary. The more team members your business has, the higher the level of protection needed, and the more robust the firewall should be.
Larger businesses should look to purchase an enterprise-level firewall to protect the network from overloading.
Firewalls should be straightforward to install, easy to manage and offer good value for the cost. Your IT team should be able to adjust the firewall either remotely or at the server room directly.
Another important feature to consider is built-in high availability. If your business firewall were to shut down for any reason, it will but over to a secondary firewall and resume operations.
This feature isn’t too important for small businesses that can operate without a firewall for a short time while it’s being restored.
However, for large businesses with hundreds or thousands of customers’ data to protect, built-in high availability is crucial to prevent dangerous exposure if your primary firewall stops working.
Wrapping Up – Some More Things to Consider
Be sure to add all layers of network security in addition to firewalls. It can be overwhelming but take the time with your IT team to come up with the best overall needs.
Great firewalls include multiple ways to filter out traffic, but also allow for customization to set specific roles. Your IT team should develop a plan to filter the right traffic in and out based on your team's needs.
If you want your business to have a well-rounded and impenetrable security system, you should also consider including an intrusion detection system (IDS). An IDS is a piece of software or hardware that monitors traffic moving on the network. When the IDS picks up suspicious activity, it will alert your IT team exactly where it is.