Final answer:
An Intrusion Detection System (IDS) or an Intrusion Prevention System (IPS) monitors network hardware to identify and stop attacks. These systems analyze network traffic in real-time, alert administrators, and can block or counteract threats.
Step-by-step explanation:
The type of device that monitors a network's hardware to help security administrators identify and stop attacks in progress is generally known as an Intrusion Detection System (IDS) or an Intrusion Prevention System (IPS). These systems are critical for maintaining network security because they provide real-time analysis of network traffic. The IDS/IPS can identify suspicious activity that may indicate a security threat, such as an ongoing attack or unauthorized access, and take appropriate actions to mitigate these threats. This can include alerting administrators, blocking suspicious traffic, or even automatically counteracting against the attack.
Regarding the specific scenario where a device identifies and tracks all cell phones trying to connect within a certain radius, this could suggest a more specialized surveillance technology. While this capability is not typically within the scope of standard IDS/IPS functionalities, there are certainly technologies that enable law enforcement (and potentially criminals) to remotely activate a phone's microphone and camera, effectively turning it into a covert listening device. It is also important to note that the usage of such technology would generally require a warrant or fall under specific legal regulations due to privacy concerns.