Which device supports the use of SPAN to enable monitoring of malicious activity?

The device that supports the use of SPAN (Switched Port Analyzer) to enable monitoring of malicious activity is the:

Cisco Catalyst switch

SPAN, also known as port mirroring or port monitoring, is a feature on Cisco Catalyst switches that allows the copying of network packets seen on one switch port (or an entire VLAN) to another switch port, where the packet can be analyzed. This is commonly used for network troubleshooting and for security monitoring purposes.

1. Cisco IronPort: Cisco IronPort is a line of appliances designed for email and web security. They include advanced threat prevention capabilities and are often used to control outbound messaging, prevent spam, and manage encryption. While these appliances provide security monitoring, they do not utilize the SPAN feature, which is specific to network switches for mirroring traffic.
2. Cisco Security Agent: Cisco Security Agent was an endpoint security solution that provided threat protection for server and desktop computing systems. It focused on policy enforcement, malware protection, and threat mitigation at the host level, not on the network traffic monitoring that SPAN facilitates. The Cisco Security Agent does not support network traffic mirroring.
3. Cisco Catalyst switch: This is the correct answer. Cisco Catalyst is a series of network switches that provide connectivity and network management to enterprise networks. The SPAN feature on Cisco Catalyst switches allows you to select network ports or VLANs to be monitored and to send a copy of the traffic seen on these ports or VLANs to another port on the switch where it can be captured and analyzed. This is useful for monitoring for malicious activity without interfering with the normal flow of network traffic.
4. Cisco NAC (Network Admission Control): Cisco NAC was a set of security solutions that enforced security policy compliance on devices seeking to access network resources, ensuring that they met certain security criteria before they were allowed access. While it played a role in security monitoring by controlling access based on compliance, it did not support the SPAN feature, which is for monitoring and analyzing traffic on a network switch.

In summary, among the listed devices, only the Cisco Catalyst switch has the capability to support the SPAN feature, which enables the monitoring of network traffic, including potentially malicious activity.