networks//firewall

A firewall is a network control that permits or blocks traffic according to rules about source, destination, protocol, port and sometimes application-layer content. It controls reachability. It does not decide whether every permitted action is benign.

A firewall is a network control that permits or blocks traffic according to rules about source, destination, protocol, port and sometimes application-layer content. It controls reachability. It does not decide whether every permitted action is benign.

That limitation is not obsolescence. Preventing a workload from contacting most of the network remains one of the cheapest ways to shrink attack surface and blast radius, and rules on network egress decide which outbound destinations a workload can reach at all. Behavioral monitoring answers a different question after or during allowed communication: XDR correlates behavior across domains, where the firewall only enforces the rules of reachability.

The firewall is still the door. It simply cannot recognize every dangerous guest.