Next Generation Firewall

A next generation firewall (NGFW) builds on a classic firewall but additionally looks inside the content of data packets instead of only checking source, destination and port. That lets it recognise which application is actually generating a connection, even when it runs over an ordinary port. This closes a gap plain port filtering leaves open, since many applications today share the same standard ports as normal web traffic.

In practice, an NGFW allows rules at the application level, such as 'allow video calls but block file transfer over the same channel', instead of only blocking or allowing entire ports. Many NGFW devices also include intrusion prevention, which recognises known attack patterns inside the traffic itself. Day to day, this usually becomes visible through reports showing which applications and destination servers are actually being used on the network.

An edge case worth noting: not every firewall marketed as modern is automatically an NGFW – what matters is whether it actually inspects connection content or only header data. An NGFW also does not fix poor network segmentation on its own; it still only controls the boundary where it is deployed.