HPE Aruba Networking ClearPass Policy Manager (CPPM) uses device profiling to identify and classify endpoints on the network, enabling granular access control based on device type, OS, or other attributes. CPPM supports both passive and active profiling methods.
Option C, "CPPM can analyze settings such as TTL and time window size in endpoints' TCP traffic in order to fingerprint the OS," is correct. TCP fingerprinting is a passive profiling method used by CPPM. It involves analyzing TCP packet headers, such as the Time To Live (TTL) value and TCP window size, which vary between operating systems (e.g., Windows, Linux, macOS). CPPM captures this traffic (e.g., via mirrored traffic from a switch or controller) and matches the TCP attributes against its fingerprint database to identify the OS of the endpoint.
Option A, "CPPM can use Wireshark to actively probe devices, analyze their traffic patterns, and construct an endpoint profile," is incorrect. CPPM does not use Wireshark for profiling; Wireshark is a third-party packet analysis tool. CPPM has its own built-in profiling engine and does not rely on external tools like Wireshark for active probing.
Option B, "CPPM can use SNMP to configure Aruba switches and mobility devices to mirror client traffic to CPPM for analysis," is incorrect. While CPPM can receive mirrored traffic for profiling (e.g., via SPAN or mirror ports), it does not use SNMP to configure the mirroring. The configuration of traffic mirroring is typically done manually on the switch or controller (e.g., using a datapath mirror on an MC), not via SNMP by CPPM.
Option D, "CPPM can analyze settings such as TCP/UDP ports used for HTTP, DHCP, and DNS in endpoints' traffic to fingerprint the OS," is incorrect. While CPPM does analyze HTTP, DHCP, and DNS traffic for profiling, it does not fingerprint the OS based on TCP/UDP ports. Instead, it uses attributes like DHCP Option 55 (for DHCP fingerprinting) or HTTP User-Agent strings (for HTTP fingerprinting) to identify devices, not the ports themselves.
The HPE Aruba Networking ClearPass Policy Manager 6.11 User Guide states:
"ClearPass supports TCP fingerprinting as a passive profiling method to identify the operating system of endpoints. By analyzing TCP packet headers, such as the Time To Live (TTL) value and TCP window size, ClearPass can fingerprint the OS of a device. For example, Windows devices typically have a TTL of 128, while Linux devices often have a TTL of 64. These attributes are matched against ClearPass’s fingerprint database to classify the device." (Page 248, TCP Fingerprinting Section)
Additionally, the ClearPass Device Insight Data Sheet notes:
"ClearPass uses passive profiling techniques like TCP fingerprinting to identify device operating systems. By examining TCP attributes such as TTL and window size, ClearPass can accurately determine whether a device is running Windows, Linux, macOS, or another OS, enabling precise policy enforcement." (Page 3, Profiling Methods Section)
[References:, HPE Aruba Networking ClearPass Policy Manager 6.11 User Guide, TCP Fingerprinting Section, Page 248., ClearPass Device Insight Data Sheet, Profiling Methods Section, Page 3.===========]
