A firewall is an important security layer that serves as a barrier between private networks and the outside world. Firewall designs have progressed dramatically over the last four decades, from first-generation, stateless firewalls to next-generation firewalls. Organizations may now pick from a variety of firewall types, including application-level gateways (proxy firewalls), stateful inspection firewalls, and circuit-level gateways, and even combine them for a full security solution.
A firewall is a security technology that monitors incoming and outgoing network traffic in order to detect and prevent dangerous data packets using specified rules, enabling only genuine information to access your private network.
Different Types of Firewalls
There are mainly four types of firewalls and categorized into : such as software firewalls, hardware firewalls, or both, depending on their structure.
- Packet-filtering firewalls
- Circuit-level Firewall
- Stateful inspection firewalls
- Application-layer firewalls
Packet filtering firewall
Packet filter firewall is the oldest and most basic type of firewall. Working at the network level, they monitor data packets against source IP and destination IP, protocols, pre-defined rules for source ports and destination ports to determine whether to send packets or not. . A packet filter firewall is essentially non-static, monitoring each packet independently without an established connection or tracking the previous packet on that connection. This severely limits the ability of these firewalls to protect against sophisticated threats and attacks.
Session-level operations Verify circuit-level gateway transmission control protocol (TCP) connections and track active sessions. They are similar to packet filter firewalls because they perform a single inspection and use less resources. However, they operate at a higher level of the Open System Interconnection (OSI) model. Basically, they determine the security of the established connection. When an internal device initiates a connection with a remote host, a circuit-level gateway creates a virtual connection on behalf of the internal device to hide the internal user’s identity and IP address.
Stateful Inspection Firewalls
Stateful inspection firewalls, and packet inspections to provide the best security for verifying and tracking installed connections.
Once the connection is established, they can create a country table with source IP, destination IP, source port and destination port. Based on this information, they dynamically create their own rules to allow for expected incoming network traffic without relying on a set of hard code rules. They simply drop a data packet that does not include a verified active connection.
Application level gateway
Application-level gateways, also known as proxy firewalls, are run by proxy devices at the application level. Connections are made through proxy firewalls, instead of outsiders having direct access to your internal network. External clients send requests to the proxy firewall. The proxy firewall receives a request from the external client.
Which is Best For Your Business?
There is no one-size-fits-all solution that can meet each organization’s specific security needs. Each sort of firewall has its own set of advantages and disadvantages. Stateful inspection and proxy firewalls can degrade network performance, whereas packet filtering firewalls are simple but offer limited protection. Although next-generation firewalls appear to be a complete package, not every business has the funds or resources to adequately setup and administer them.