Discuss ways a system administrator can reduce system scanning by hackers.

A system administrator can reduce system scanning by hackers using several methods.

First, configure network firewalls to block inbound connections to unused or restricted ports. Implement rate limiting on services prone to scanning, such as SSH or RDP. This helps prevent attackers from extensively mapping the network. For example, blocking ICMP echo requests can prevent network mapping through ping sweeps.

Deploy Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS). An IDS detects common scanning patterns, like sequential port scans. An IPS automatically blocks the source IP address performing the scan. An IPS can, for instance, drop packets from an IP address that attempts to connect to many closed ports in a short time.

Use network segmentation, with VLANs and internal firewalls, to limit the reach of a scan within the network. If an attacker gains access to one segment, their ability to scan and map other sensitive segments is restricted.

Disable all unnecessary services and close their corresponding ports on servers and network devices. This reduces the attack surface. Configure services to obscure version numbers or other identifying banners that could aid attacker reconnaissance. Using honeypots can also divert scanning attempts to decoy systems, allowing observation of attacker behavior without exposing critical assets.