Choosing the proper security firewall is essential in ensuring your network’s safety and privacy. There are several different types of firewalls, including Host, Proxy, Network, and Circuit-level gateways. These different types of firewalls are each designed to provide specific levels of protection.
Host firewalls
Besides protecting against malware and other malicious programs, a host firewall also helps to control outgoing traffic. For example, it protects computers when they connect to an enterprise network or an external WiFi network.
Today, there are several host-based firewalls on the market. These include Microsoft Windows Firewall, macOS, and Linux/Unix. Choosing the proper firewall depends on the technical requirements of the organization.
Firewalls are designed to inspect packets and determine their behavior based on criteria. They can be either stateful or transparent. The latter does not route the packets but performs basic filtering.
The ICMP information request message was created to support self-configuring systems. Therefore, it is rarely used for network discovery. However, it can be helpful for network troubleshooting.
All TCP and UDP packets have a source and destination address. The boxes also have flags that indicate the connection state. These include the SYN, ACK, and RST flags. In some cases, the flags are not necessary. Some applications may only require the packet sorted by port or source/destination addresses.
The firewall logs should be configured to record the source and destination IP addresses and the protocol to ensure the firewall is doing its job. A successful attack can be detected in these logs. These logs should also be available in read-only format.
Network-based firewalls
Using a firewall to protect your network is essential, and you’ll want to know how to determine which type is best for your organization. There are three main types of firewalls: host-based, network-based, and application-based. When looking at these options, consider the technical objectives of your network.
Typically, host-based firewalls are installed on a single computer and are designed to protect that computer from unauthorized access. However, they can also affect traffic from the local network or the Internet. In a more extensive enterprise network, they can be used to protect multiple computers. A host-based firewall can be easier to manage than a network-based solution, providing an excellent micro-segmentation layer.
Unlike a host-based firewall, a network-based firewall is a separate device that can be deployed to protect a whole computer network. These firewalls are also known as hardware or software appliances.
In a network-based firewall, the differences between each firewall type and incoming traffic are filtered according to a set of rules. An administrator can define these rules, or they can be based on security policies. For example, a rule may be created that says that the HR department cannot access the code server. In this case, the firewall would reject the incoming traffic.
Packet filtering firewalls look at every packet passing through the network. Then, they compare the box to specific criteria, such as the source or destination IP address, the number of hops, or a particular port. If the packet fails to meet these criteria, it’s usually dropped.
Proxy-based firewalls
Detecting advanced threats using a proxy firewall is a crucial way to enhance security in the network. With a proxy firewall, your organization can analyze the content of all incoming and outgoing network packets. This allows your organization to detect the presence of advanced malware.
Despite its advantages, a proxy firewall can slow down your network. This is because it performs deep inspections on incoming data packets. The actual contents of a package are checked against user-defined rules. Then, the firewall will decide whether to allow or deny a connection request.
This type of firewall is based on the Domain Name System (DNS) and Internet Control Message Protocol (ICMP). A proxy server is installed between a local computer and a network. It enables a client to connect to different servers by allowing indirect network connections.
Besides, it monitors network traffic for core internet protocols, like HTTP and Hypertext Transfer Protocol (HTTP). Depending on the proxy-based firewall you install, it may watch other network layers.
Proxy-based firewalls were first used to monitor the websites a user could access on the Internet. However, since then, the technology has expanded to include other features. This provides error detection and more refined setup control.
Another key feature is applying security levels to specific users, groups, or locations. A proxy firewall can also provide extensive logging capabilities.
Circuit-level gateways
Unlike a packet filter, a circuit-level gateway does not check the contents of individual packets. Instead, it relies on data in the TCP session-layer protocol headers to determine whether a packet’s content is legitimate.
The advantage of using a circuit-level gateway is that it provides proxy server protection. Without it, a hacker could easily slip malicious packets through the firewall. In addition, using a circuit-level gateway helps protect trusted networks from spoofing attacks.
A circuit-level gateway is a stand-alone security system that acts as a proxy for an internal computer or application. It relays data from the internal computer to a remote server and vice-versa. It also enables applications to traverse a firewall securely.
Unlike an application-level gateway, a circuit-level gateway operates at a higher layer in the OSI reference model. This makes it more similar to a Level-5 proxy. It allows applications to send and receive packets and other data without being restricted by an internal firewall.
A circuit-level gateway is often packaged with an application-level gateway. In addition to providing proxy server protection, the circuit-level gateway can extend the number of services supported by an application-level gateway.
Despite its advantages, a circuit-level gateway has some disadvantages. One of the primary disadvantages is that the circuit-level gateway does not filter the packets. Instead, it copies and forwards them, regardless of their contents. This means it may be unable to filter out any unwanted data from a device.
