What does SPI stand for in cyber security
What is SPI?
Stateful packet inspection (or dynamic packet filtering) is a technology that monitors active connections and checks whether incoming data packets match those connections. It then decides whether to allow or deny them to pass through the firewall.
In short, devices transmit data in packets so that the receiving side can process them more easily. One large block of data can be divided into several packets. But hackers can hack into these packets to harm the receiving server. This is where the SPI firewall checks to see if these packets are legitimate and match an already established connection. It rejects packets that do not belong to a trusted connection, thereby minimizing the possibility of hacking.
What is an SPI firewall?
An SPI (stateful packet inspection) firewall protects devices by checking incoming packets against existing connections.
A normal firewall does inspection on static values, such as the source or destination address. It does not take into account the packet connection traffic and applies the same set of rules to all packets and cannot receive any information about its connection. These firewalls cannot be configured to open and close sessions. They also cannot detect if packets are coming from a legitimate IP address. Therefore, they are not as secure as SPI firewalls, but they are faster.
How do SPI firewalls work?
An SPI firewall can memorize the attributes of each connection and use this information to determine the reliability of the packet. It stores this information by examining the packets and setting rules. Because of this, it sees the entire context of the packet, not just the contents.
With this memory, the SPI firewall does not need to thoroughly examine every packet, so it works faster than deep packet inspection (DPI). The latter deconstructs packets to see if they are properly formed and if they contain any malicious code. DPI is used for a variety of purposes, including network management, security, data mining, or Internet censorship. It provides security through speed reduction.