What is a firewall?

Firewalls protect a computer network from a variety of dangerous and hacker attacks. It can be implemented as hardware or software or a combination of them. It must be connected to at least two network interfaces. One to be protected (secure internal network) and the other to be attacked (insecure external network and the internet in general).

In general, firewalls offer many features and solutions to increase network security as well as various policies in private and public companies.

How does the firewall work?

The firewall will check the data passing through the network to comply with the rules defined by the ACL (Access Control List). It is provided by the network administrator, and will only be allowed to send data packets if approved in terms of ACL.

It has been the first line of defence in network security for many years and can filter content based on address, protocols, closed features, and many more.

Features and facilities

Firewalls have the following features and facilities:

• Blocking inputs depending on source or destination
• Blocking outputs depending on the source or destination
• Blocking network traffic according to the content sent or received
• Provide internal resources
• Provide communication to the internal network
• Reporting of firewall and network traffic activities

Types of firewalls

There are several types of firewalls to secure your network such as:

• Proxy server firewall
• Packet filter firewall
• Circuit level firewall
• Stateful multilayer inspection firewall

Proxy server firewall

What is a firewall Proxy Server?

Most modern firewalls distinguish between filter packages and proxy server services. A proxy firewall server is a program that acts as an intermediary between two-wheeled end systems. Firewall proxy servers work in the firewall application layer, where both ends of a connection are forced to make a meeting through a proxy. They do this by creating and executing a process on the firewall that provides a service if the mirror is in the end host of the mirror.

Converts sessions

A firewall proxy server essentially converts a two-way session to a four-way session which mimics the middle process of two real hosts. Because they work at the application level, proxy servers are also referred to as program layer firewalls. A proxy service must be running for any type of Internet application supported by Firewall – a simple email transfer proxy (SMTP) for email, an HTTP proxy for web services, and more.

Proxy servers almost always transfer one-way settings from the internal network to the external network. In other words, if an internal user wants to access a website via the internet, the packages that make up this request are processed through the HTTP server before being sent to the website.

Perform useful functions

Returned packages from the website are in turn processed by the HTTP server before being sent to the internal user host. Because proxy firewall servers focus all the activities of a program on a single server, they provide an ideal opportunity to perform a variety of useful functions.

Having the program running properly on the firewall provides an opportunity to inspect packets for items other than source/destination addresses and port numbers. That’s why almost all modern firewalls have some sort of proxy server architecture. For example, input packets that are deployed to the server they can be inspected so that they can send their information (for example, FTP server) to see that they contain any writing command. In this way, the proxy server can only allow connections containing read commands.

This type of firewall examines the packets used in the application layer. The proxy server does not allow the passage of FTP (File transfer protocol), Telnet, and traffic, and because it works in the application layer, it can filter commands such as HTTP (post and get).

Packet filter firewall

What is a packet filter firewall?

This type of firewall is one of the first generations of firewalls that have entered the digital arena for about 30 years. High speed, low cost in configuration and ease of operation are the advantages of this firewall.

These firewalls work on the network layer and are placed at the entrance of the network and control the entry of packets using a set of rules and regulations. These decisions are made in IP (Read more “What is an IP?”), TCP and UDP protocols. This type of firewall has a high speed and no information is used in the layer. To know more about TCP and UDP please read this “What is TCP and UDP stands for?”

Functions of packet filter firewall

The function of this feature in the firewall is to check the sent or received packets individually. The purpose of the check is to check the port number, address and protocol of origin and destination. If this package fails to comply with the rules and regulations of this type of firewall, the package will not be sent and will not reach its destination. These types of firewalls usually work on OSI networks and may be vulnerable to IP attacks because they independently examine packets.

Circuit level firewall

What is circuit level firewall?

A circuit-level gateway is a firewall that ensures the connection security between UDP (User Datagram Protocol) and TCP (TCP = Transmission Control Protocol) and between transport and application layers of an Open Systems Interconnection (OSI) network model how the session layer works. A proxy server is a security barrier between internal and external computers, while a circuit-level gateway is a virtual connection between the proxy server and the internal client.

Functions of circuit level firewall

For example, when a user website access request passes through the circuit gateway, basic internal user information, such as B. the IP address, exchanged to get proper feedback. The proxy server then forwards the request to the webserver. After receiving the request, the external server sees the IP address of the proxy server but does not receive any internal user information. The web or real server sends the proxy server a correct response, which is forwarded to the client or end-user via the circuit level gateway.

These types of firewalls work in the OSI model session layer. In fact, TCP monitors handshake between two remote computers to check if the session is legal. These types of firewalls hide private network information.

Stateful multilayer inspection firewall

What is stateful multilayer inspection firewall?

These types of firewalls are a combination of the previous three types and filter packets in the network layer to check the legality of the session and evaluate the content of the packages in the application layer.

Packet filtering function?

These type firewalls are also known as dynamic packet filtering. This firewall leaves all communication channels open because this type of firewall has a table that when a package comes from somewhere, it looks at the information in that package and compares that information with its standard table to see if it is possible to communicate. Whether or not there is, then if that information is consistent with the table, the packet is entered and passed to the recipient; otherwise, the packet is blocked and returned because it did not comply with the rules of the firewall table.

This type of firewall tracks the packets sent and received, and only allows packets that comply with the rules of this type of firewall table to enter and exit. These types of firewalls, even with all the features mentioned, are resistant to dos attacks they are vulnerable. Its high security and high cost are some of the advantages and disadvantages of this service.

Traffic restriction

But stateful filters are a bit more complex and store and store information such as source and destination IPs and ports used, as well as data from other layers in the database. By default, the firewall does not allow any traffic from the external network to the internal network, but the return traffic, the specifications of which are available in the database, is excluded and the entry permit is issued.

Advantages of stateful multilayer inspection firewall

• Ability to use as the main tool for unwanted traffic
• More dynamic method than the previous method
• Ability to prevent spoofing attacks and DOS

Disadvantages of stateful multilayer inspection firewall

• It may not be able to prevent some programs
• Can not control and review all protocols.

Ability of firewall

A firewall is a network security system that monitors inbound and outbound traffic in accordance with defined rules. Firewalls are usually divided into two categories such as:

• Network firewalls
• Host-based firewalls.

The network firewall monitors the input and output traffic of the network, but the host-based firewall is placed on a host machine and controls the input and output traffic of the network on this host. Because a firewall is usually placed at the entrance to a network, it is also used to translate network addresses.

The firewall should be able to record and alert events, visit large volumes of information packages, simplify configuration, security and redundancy, including hardware, network and software.  Firewalls can have one or more network cards.

Why do you need security through the firewall in Dallas?

Important facilities

One of the most important and best things about firewalls is that access to computers on the network stops you from outside the network. There are several ways to access and exploit unsafe computers:

• Login remotely
• Backdoor programs
• SMTP session theft
• Operating system security flaws
• Denial of service
• Email bombs
• Macro
• Virus
• Spam
• Bomb route change
• Source routing

It is difficult and in some cases impossible to filter some of the items in the list above using firewalls. Although some firewalls also have antivirus, installing separate antivirus on all network systems is a valuable investment. The level of security you consider determines how many of these threats can be stopped by your firewall.

Highest level of security

The highest level of security is to block everything. But it is clear that such a thing calls into question the philosophy of using the Internet in general. But the usual rule is to block everything first and then decide what kind of traffic is allowed to pass through your firewall and open it. You can also restrict the traffic that passes through the firewall so that only certain types of information such as emails are allowed to pass.

It is very helpful to have a good network manager who understands the needs and determines the type of information allowed. For most of us, the best thing to do is to work with the default firewall settings, unless we have a specific reason to change it.

How to choose the best security firewall in Dallas?

Before choosing a firewall, you must first consider the conditions and needs of the organization and choose a suitable system to ensure the security of the organization, taking into account the following:

• How much does it cost to buy a firewall?
• A firewall in the small and large scale used for?
• Is it possible to update the firewall in Dallas?
• Did manage firewall easily used for service and needs?
• What resources and training available for the firewall?

The bottom line

Finally, the answer to all these questions lies in waiting for your network of firewalls, which features of firewalls are most important to you, such as an easy menu, high speed, high security, high security, low cost, good support, your admin familiarity with firewall and

Consult with Firewall & security management in Dallas

In this article, you see that the firewall plays an important role in ensuring the security of computer networks and control the incoming and outgoing traffic which is very important. Please fix an appointment with our highly skilled IT Consultant to discuss regarding firewall & security management in Dallas

Contact Intrigue IT now. For more details call us here “469-878-3479” or send us an email “sales@intrigueit.com”.