HPE Aruba Networking ClearPass Policy Manager (CPPM) uses TCP fingerprinting as a passive profiling method to classify endpoints by analyzing TCP packet headers (e.g., TTL, window size) to identify the operating system (e.g., Windows, Linux). The company in this scenario has Mobility Controllers (MCs), campus APs, and AOS-CX switches, and wants to use CPPM’s TCP fingerprinting capabilities for endpoint classification.
TCP Fingerprinting: This method requires CPPM to receive TCP traffic from endpoints. Since CPPM is not typically inline with network traffic, the traffic must be mirrored to CPPM for analysis. This is often done using a SPAN (Switched Port Analyzer) port or mirror port on a switch or controller.
Option A, "You will need to mirror traffic to one of CPPM’s span ports from a device such as a core routing switch," is correct. For CPPM to perform TCP fingerprinting, it needs to see the TCP traffic from endpoints. This is typically achieved by mirroring traffic from a core routing switch (or another device like an MC) to a SPAN port on the CPPM server. For example, on an AOS-CX switch, you can configure a mirror session with the command mirror session 1 destination interface source vlan to send traffic to CPPM. This is a key consideration for enabling TCP fingerprinting.
Option B, "ClearPass admins will need to provide the credentials of an API admin account to configure on HPE Aruba Networking devices," is incorrect. TCP fingerprinting does not require API credentials. It is a passive profiling method that analyzes mirrored traffic, and no API interaction is needed between CPPM and Aruba devices for this purpose.
Option C, "AOS-CX switches do not offer the support necessary for CPPM to use TCP fingerprinting on wired endpoints," is incorrect. AOS-CX switches support mirroring traffic to CPPM (e.g., using a mirror session), which enables CPPM to perform TCP fingerprinting on wired endpoints. The switch does not need to perform the fingerprinting itself; it only needs to send the traffic to CPPM.
Option D, "TCP fingerprinting of wireless endpoints requires a third-party Mobility Device Management (MDM) solution," is incorrect. TCP fingerprinting is a built-in capability of CPPM and does not require an MDM solution. For wireless endpoints, the MC can mirror client traffic to CPPM (e.g., using a datapath mirror), allowing CPPM to perform TCP fingerprinting.
The HPE Aruba Networking ClearPass Policy Manager 6.11 User Guide states:
"TCP fingerprinting requires ClearPass to receive TCP traffic from endpoints for analysis. A key consideration is that you must mirror traffic to one of ClearPass’s SPAN ports from a device such as a core routing switch or Mobility Controller. For example, on an AOS-CX switch, configure a mirror session with mirror session 1 destination interface source vlan to send traffic to ClearPass for TCP fingerprinting." (Page 248, TCP Fingerprinting Section)
Additionally, the HPE Aruba Networking AOS-8 8.11 User Guide notes:
"For ClearPass to perform TCP fingerprinting on wireless endpoints, the Mobility Controller can mirror client traffic to ClearPass using a datapath mirror. For wired endpoints, an AOS-CX switch can mirror traffic to ClearPass’s SPAN port, enabling TCP fingerprinting without requiring additional support on the switch itself." (Page 351, Device Profiling with CPPM Section)
[References:, HPE Aruba Networking ClearPass Policy Manager 6.11 User Guide, TCP Fingerprinting Section, Page 248., HPE Aruba Networking AOS-8 8.11 User Guide, Device Profiling with CPPM Section, Page 351.===========]