What additional functionality did second-generation firewalls offer over early packet-filter firewalls?

Second-generation firewalls advanced beyond early packet-filtering firewalls by incorporating the ability to continuously examine the conversations between endpoints. This means they can track and analyze the state of a network connection in real-time, allowing for more sophisticated inspection of traffic patterns and interactions. Unlike simple packet filters, which only inspect headers and allow or deny traffic based on predefined rules, these firewalls maintain context about ongoing sessions, which enables them to detect more complex threats and maintain security policies that consider the entirety of a communication session.

This continuous examination allows second-generation firewalls to offer deeper insight into the traffic flow and to make more informed decisions about what traffic should be allowed through or blocked, based not just on static rules but on the behavior of the traffic itself. This feature plays a critical role in enhancing network security, as it helps in identifying suspicious activities that may not be evident through basic packet filtering alone.