As we all know, cyber attacks increase exponentially due to the storage of online or cloud-based data; firewall security management protects cyber attackers by protecting your system or network from malicious or unwanted network traffic. It can also control malicious software from accessing a system or network through the internet.
In this blog, we shall go through:
- What are the 3 types of firewalls?
- The functions of firewalls, and
- How does a firewall work?
What is a Firewall?
Software that filters incoming and outgoing network traffic according to user-defined rules is known as a firewall. A firewall’s main objective is to lessen or completely stop all illegitimate network communications while enabling all legitimate communications to proceed freely. In most server infrastructures, firewalls offer a crucial layer of security that keeps intruders from accessing your servers for nefarious purposes when integrated with other measures.
To make you understand stateful software firewalls, such as tables and FirewallD, relate to cloud servers, this guide will cover how firewalls operate. We’ll begin by briefly overviewing TCP packets and the kinds of firewalls. Then, we’ll discuss a range of issues pertinent to stateful firewalls.
To learn more about firewalls, join Ethical Hacking Online Course and understand the working of firewalls, IDS, IPS, Firewalls, and Honeypots.
Transport Control Protocol Network Packets
Let’s take a quick look at the Transport Control Protocol (TCP) network traffic before discussing the various types of firewalls.
TCP network traffic is transferred over a network via packets, containers for data and packet headers that include addresses and other control information. While the control information in each packet aids in ensuring the proper delivery of the data, the components it contains also give firewalls several ways to compare packets to firewall rules.
It is crucial to remember that for the receiver to process incoming TCP packets effectively, it must also transmit outgoing acknowledgement packets to the sender. It is possible to ascertain the connection state by combining the control information in the incoming and outgoing packets.
Types of Firewalls
Let’s quickly go over the three fundamental categories of network firewalls:
- Application layer
- Stateful, and
- Packet filtering
Stateless firewalls, also known as packet filtering firewalls, operate by isolating each packet for examination.
They cannot access the connection state. As a result, it can only accept or reject packets based on their respective headers.
Stateful firewalls are substantially more adaptable than stateless firewalls because they can identify the connection state of packets. Before applying any firewall rules to the traffic, they gather related packets to identify the connection state.
Application firewalls take network traffic analysis one step further by evaluating the transmitted data, allowing it to be compared to firewall rules that are particular to individual applications and services. Additionally, these are called proxy-based firewalls.
Hardware solutions, such as routers or firewall appliances, can also provide firewall capabilities in addition to firewall software, which is available on all current operating systems.
To become an ethical hacker, join Ethical Hacking Course in Chennai and gain an in-depth understanding of hacking techniques, firewall security software, Cryptography, and Social Engineering would help you become a professional hacker.
Firewall Rules
As we already said, network traffic that passes through a firewall is compared against the rules to ascertain whether it should be permitted. It’s simple to explain firewall rules by giving a few instances.
Assume you have a server that follows the following list of firewall rules for incoming traffic:
- Accept incoming traffic to ports 80 and 443 on the public network interface, both new and existing traffic (HTTP and HTTPS web traffic)
- Reduce incoming traffic to port 22 emanating from the non-technical staff’ IP addresses in your office (SSH)
- Accept incoming traffic from your office’s IP range on port 22 (both new and existing traffic) (SSH)
To learn more about firewall security systems, you can join Ethical Hacking Course In Bangalore and acquire a better understanding of how does firewall work, Intrusion Detection System (IDS) and Evasion Tools.
Default Policy
A chain of firewall rules frequently does not explicitly cover every scenario that could arise. Because of this, firewall chains should always have a default policy containing one action accept, reject, or drop.
Let’s assume the drop policy is the default. Any attempt by a computer to connect over SSH from a location other than your workplace would result in the traffic blocking because it does not comply with any rules.
If the default policy were set to accept, anyone from your non-technical staff members could connect to any open service on your server. Because it just holds a portion of your staff out, this would be an example of a firewall that is very poorly set up.
Incoming and Outgoing Traffic
A firewall maintains a different set of rules for either case, incoming or outgoing traffic. Traffic that originated elsewhere, incoming traffic, is processed differently than outgoing traffic that the server sends. Because a server is often reliable, it usually allows most outgoing traffic. However, if an attacker or a malicious application has penetrated a server, the outgoing rule set can be utilized to stop unwanted communication.
The best method to use a firewall’s security features is to list how other systems can communicate with your server, make rules that permit those interactions, and then block all other traffic. Remember that a server must have the proper outgoing rules before it can authorize itself to send outgoing confirmation to any suitable incoming connections. Including those situations in your outgoing rule set is crucial because a server frequently needs to start its outgoing traffic for several reasons, such as downloading updates or accessing a database.
Firewall Software and Tools
After discussing how firewalls operate, let’s look at some popular software programmes that can assist in configuring an efficient firewall. Although there are many more firewall-related packages, these are the most common and useful.
- ESET Endpoint Security
- website
- ManageEngine Firewall Analyzer
- NameFree TrialFeaturesLink
- ManageEngine Firewall Analyzer
- TotalAV
- GlassWire Firewall
- ZoneAlarm
Now, you would have understood the stateless firewall, how does firewall work, the firewall server, and what are the 3 types of firewalls. So, to learn more about firewall systems, you can join an Ethical Hacking Course in Coimbatore and learn the components of a firewall and its rules.