Firewalls are one of the best ways to ensure network security. Large corporations, organizations and, start-ups use firewall protection to secure their network and filter the incoming traffic. The traffic comes from various external sources, and if not careful, any hacker can send a malicious virus hidden in the traffic. Also, many corporations don’t want to give access to irrelevant personnel even within their company. A firewall restricts access to those that shouldn’t be accessing the network. Let’s discover more about the firewall and especially, the SPI Firewall.

So, what is SPI?

SPI is an acronym for Stateful packet inspection. It decides whether to grant permission to someone accessing the network by matching the data packets coming from that source to the integrated active connections.

These data packets are used because it is easier to transmit and receive them. Even if someone is sending a larger unit of data, it will be divided into small data packets before it reaches the servers. However, the threat of hacker integrating malicious trojans or viruses in data packets always remain. The SPI firewall filters this data and rejects any data coming from an unauthorized source.

Now, what is an SPI Firewall?

SPI Firewalls are much more effective compared to other stateless firewalls. These firewalls prevent any data packets coming from unrecognized connections. The stateless firewalls, on the other hand, cannot recognize whether the traffic is coming from an unrecognized source. It is also not possible to customize stateless firewalls, whereas, you cna customize SPI firewalls.

However, an SPI Firewalls is a bit slower compared to other firewalls due to the level of work they do. 

Well, how do SPI firewalls work?

SPI Firewalls recognizes and remembers the characteristics of connections. It, thus, uses this information to recognize the quality and validity of data packets. It thoroughly examines the data packets and stores the information.

Due to this stored memory, SPI Firewalls work faster compared to deep packet inspection firewalls. DPI firewalls, usually, break every data packet, examines the content, and only then allow the data to be transferred. This takes a while and that is why SPI  Firewalls are faster than DPI firewalls.