Terminology Index
Glossary
2953 terms
C32
Connection State
Whether and how a network connection is established and tracked, such as the stages of a TCP connection, which lets firewalls and analysts reason about traffic as conversations rather than isolated packets.
Connection-oriented protocols like TCP move through states (establishing, established, closing), and tracking this state is what lets a stateful firewall allow return traffic for a connection it permitted while blocking unsolicited packets. For defenders, understanding connection state aids investigation, distinguishing a completed conversation from a half-open scan, and is foundational to interpreting network evidence and firewall behavior.
Introduced in: Networking Foundations
Examples
- A stateful firewall allowing return traffic because it tracks the connection's state.
- Recognizing a flood of half-open connections as a scan or SYN flood.
- Using connection state in logs to tell a completed session from a blocked attempt.
