What Is a Firewall
What Is a Firewall?
A firewall is a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block clearly defined traffic based on a configured set of security rules.
Firewalls have been a first line of defense in network security for over 25 years. They establish a software and often hardware defined security border between secured and controlled internal networks that can be trusted, and untrusted outside networks, such as the Internet.
A firewall can be hardware, software, or both.
The firewall is a security device, computer hardware or software, that can help protect your network by filtering traffic and blocking outsiders from gaining unauthorized access to the private data on your computer.
Not only does a firewall block unwanted traffic, it can also help block malicious software from infecting computers within the network.
Firewalls can provide different levels of protection. The main consideration is deciding and figuring out how much protection you need.
This article can help you learn what firewalls do, and assist in providing the level of protection that will help keep your computer and data safe and secure.
Firewalls are part of your network security
Firewalls represent a first line of defense in network security.
Your home or business network is only as secure as its least protected device. That’s where a network security system comes in.
A firewall shouldn’t be your only method for securing your home network. It’s important to make sure that all of your internet connected devices, including mobile devices, have the latest operating system, web browsers, and security software.
Another thing to think about? Securing the wireless router and access points. This might include changing the name of your router from the default ID and password it was preconfigured with, modification of security options, and setting up a VLAN guest network for visitors.
What does a firewall do?
A firewall acts as security guard. It monitors attempts to gain access to your operating system and blocks unwanted traffic from unrecognized sources.
A firewall acts as a wall or filter between your computer and another network such as the internet. You could think of a firewall as a traffic controller. It helps to protect your network and information by managing your network traffic, blocking unsolicited incoming network traffic, and validating access by testing network traffic for anything malicious, such as intrusion attempts and harmful programs or apps.
Your operating system and your security software usually come with a pre-installed firewall. It’s a good idea to make sure those features are turned on. Also, make sure your security settings are configured to run updates automatically.
How does a firewall work?
To start, a firewalled system carefully studies network traffic based on rules. A firewall only welcomes those incoming connections that it has been configured to accept. It does this by allowing or blocking detailed data packets (units of communication sent over networks) based on pre-established security rules.
A firewall works like a traffic guard at the computer or the network entry point. Only trusted sources, or IP addresses, are allowed in. IP addresses are important because they identify a computer or source, just like your postal address identifies where you live.
Types of firewalls
There are software and hardware firewalls. Each format serves a different but important purpose. A hardware firewall is physical, like a broadband router placed between your network and gateway. A software firewall is internal, a program on your computer or router that works through port numbers and computer programs.
There also are cloud based firewalls, known as Firewall as a Service (FaaS). One benefit of cloud based firewalls is that they can grow with your organization. Similar to hardware firewalls, they do well with outside border security.
There are several different types of firewalls based on their structure and capability. Here is a brief list of different firewalls you can put into use, depending on the size of your network and the level of security you need.
Packet filtering firewalls
A packet-filtering firewall is a management program that can block network traffic IP rules of conduct, an IP address, and a port number. This type of firewall is the most basic form of protection and is meant for smaller networks.
While packet filtering firewalls can be helpful, they also have limits. Because all web traffic is allowed, it doesn’t block web based attacks. Additional protection is needed to tell the difference between friendly and malicious web traffic.
Stateful multi-layer inspection (SMLI) firewalls
The stateful multi-layer inspection firewall has standard firewall abilities and keeps track of established connections. It filters traffic based on state, port, and rules of conduct, along with manager defined rules. This involves using data from prior connections and packets from the same connection.
Most firewalls depend 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 tell the difference between good and bad web traffic, so you may need additional software.
Next-generation firewalls (NGFW)
Next-generation firewalls are an improvement of packet filtering and stateful inspection firewalls. They have more levels of security, going beyond standard packet filtering to inspect the complete packet That means not just the packet header, but also a packets contents and source. NGFW can block more advanced security threats like newer harmful programs and apps.
Network address translation (NAT) firewalls
A NAT firewall can test and evaluate internet traffic. NAT can also automatically block communications. In other words, it only accepts inbound web traffic if a device on the LAN or private network requested it.
Host based firewalls compared to network based firewalls
There are differences between host based and network based firewalls: with benefits of having both in place.
Network firewalls filter traffic going to and from the internet to secured local area networks (LAN). They usually are used by businesses that need to protect a large network of computers, servers, and workers. A network based firewall can monitor communications between company computers and outside sources. It can also restrict certain websites, IP addresses, and other undesired services.
Host based firewalls function similarly, but are stored locally on a single computer or device. A host based firewall is a software computer program or a suite of computer programs that allows for more customization. They are installed on each server, control incoming and outgoing traffic, decide whether to allow traffic to individual devices, and protect the host.
You may already be practicing certain safe computer and internet security policies, including the following suggested best practices;
You don’t click on unknown links or attachments.
You only log on to trusted known websites.
You never give out any personal information unless it is completely and totally necessary.
You have strong, unique, complex passwords for each online account that you update often.
If you use the internet, it’s smart to have a firewall in place. Online threats are persistent and evolving. It’s important to use available techniques to help protect your network, and the personal information stored on your network computers against known and unknown cyber threats.
Here are the three main risks of not having a firewall:
Open Access
Without a firewall, you’re accepting every connection into your network from anyone. You wouldn’t have any way to detect incoming threats. That could leave your devices able to be hurt by evil and cruel users.
Lost, Stolen, or Corrupted Data
Not having a firewall could leave your devices exposed, which could allow someone to gain control over your computer or network. Computer criminals could delete your data, use it to perform identity theft, or cause malicious system actions.
Network Crashes
Without a firewall, attackers could overload and shut down your network. Getting it up and running again and attempting to recover your stored data could waste valuable time and money.
Firewalls are an important part of security technology, especially so when the different types of firewalls work in conjunction to provide multiple layers of network protection. Firewalls are the main components to keep your network, computer, and data safe and secure.
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