A firewall is a network or software-based security device that helps protect networks by filtering traffic and blocking unauthorised access to devices and servers. Not only does a firewall block unwanted traffic, it also helps prevent malicious software, such as viruses and ransomware, from infecting your computer.
Our day to day lives are now so dependent on the internet and smart devices that cyber security is becoming ever more important. With smartphones, cloud computing, connected cars, TV’s and more, all part of our day to day lives, there is no escaping the need for better cyber security.
Firewalls come in software and hardware formats, with each one serving a different but equally important purpose.
Hardware Firewall: A hardware firewall is physical like a broadband router and located between a network and gateway.
Software Firewall: A software firewall is a software program that runs on your computer and works through port numbers and applications.
Could-based Firewalls: Also known as firewall as a service or FaaS, cloud-based firewalls have the added benefit of being able to grow with your business and adapt to your changing needs.
Types of Firewalls
There are a variety of firewalls that can be implemented by organisations depending on the size of their network and the level of security required. The main types of firewall are:
- Proxy Service firewall
- Packet filtering firewall
- Next-generation firewall
- Stateful inspection firewall
Proxy service firewalls
A proxy service firewall protects network security by filtering messages at the application layer, acting as a gateway between the internal network and external servers on the internet. This means they can make better security decisions than firewalls which only focus on packet header information.
- Examines all communications between outside sources and devices behind the firewall
- IP addresses are concealed by default
- Harder to hack as attacker does not receive any packets directly created by the server
- Tough protocol-aware logging makes it easier to identify the methods of an attack
- Is not compatible with all network protocols
- A new proxy agent must be developed for each new application or protocol
- Network performance can slow due to the additional processing requests required
- Configuration can be more difficult than other firewall options
- Can be expensive
Packet-filtering is the most basic form of firewall security and is best used with smaller networks. This management program can block network traffic IP protocol, IP addresses, and a port number.
However, because all web traffic is allowed, additional protection will be required to protect against malicious attacks.
- Fast and efficient scanning
- Just one device can filter traffic for the whole network
- Access control lists can be awkward to set up and manage
- Traffic filtering is only based on IP address or port information
- Basic protection
Stateful multi-layer inspection (SMLI) firewalls
The stateful multi-layer inspection firewall has standard firewall capabilities and keeps track of established connections. It filters traffic based on state, port, and protocol, along with administrator-defined rules and context. This involves using data from prior connections and packets from the same connection.
Most firewalls rely on stateful packet inspection to keep track of all internal traffic. This firewall is a step above packet-filtering in its use of multi-layer monitoring.
However, it is still unable to distinguish between good and bad web traffic, so you may need additional software.
- Monitors the entire session for the state of the connection
- High level of control
- No need to open several ports to allow traffic in or out
- Provides significant logging capabilities
- Slows network communication speeds
- Most expensive option
Next-generation firewalls (NGFW)
More advanced than other firewalls, NGFW have more levels of security. They don’t stop at packet-filtering, and instead inspect a packet in its entirety, including header, content and source. That means they can block more sophisticated and evolving threats.
- Provides optimal level of filtering
- Provides more accurate insights than other firewalls
- Easy to update
- Integration with other security systems is required for maximum benefit
- More expensive than other firewalls
How to choose the best Firewall for your organisation
It’s important to devise a cyber security plan for your organisation and that means choosing the firewall that best meets your company’s needs. But with so many functions and varieties to choose from it can be difficult to decide. Here’s our list of things to consider when picking the best firewall for your business.
Different size businesses have different firewall needs. A small enterprise will naturally have far smaller firewall throughput requirements than large organisations. If a business is growing and expanding, it’s worth considering a cloud-based firewall that can grow with it.
The impact of the cloud and remote working has changed many organisations firewall and security needs. Cloud-based firewall-as-a-service solutions work wherever employees and offices may be. They can also be deployed quickly and easily.
A more traditional business model with employees based out of a single headquarters, may better suit a hardware firewall.
In-House or Outsourced
Firewalls need to be monitored as threats and networks evolve. They need to be configured and updated regularly to maintain maximum efficiency. Does your company have the time and IT expertise to manage this process, or will it need to be outsourced?
Budget will influence firewall choices, but it’s important to remember that outsourcing a firewall may be cheaper, especially if you do not have the expertise or time to do it in house.
The Future of Cyber Security
Setting up a firewall is a simple, fast, and efficient way of providing protection for your business. As more of our lives move online, threats will continue to grow and evolve, making a firewall a vital part of your organisation’s security and prosperity for years to come.