Youare configuring an HPE Aruba NetworkingGateway Ouster with AOS-10.

This question asks about 802.1X functionality in an AOS-10 environment involving Gateway Clusters.

AOS-10 Gateway/802.1X Architecture:

Authenticator:The Access Point (AP) typically acts as the 802.1X authenticator, handling EAPoL frames with the client.

RADIUS Proxy:The Gateway Cluster (specifically the cluster leader or UDG anchor) often acts as a RADIUS proxy, forwarding RADIUS messages between the APs and the central RADIUS server (e.g., ClearPass). This simplifies RADIUS configuration as the server only needs to know about the gateway cluster.  

CoA:Change of Authorization messages from the RADIUS server are typically sent to the device acting as the RADIUS client, which is the Gateway Cluster when operating in proxy mode.  

Mobility (L2 vs L3):Roaming behavior and User Designated Gateway (UDG) assignment can differ based on whether clients maintain their IP address (L2 mobility) or potentially require new IP information (L3 mobility). L2-connected gateway deployments generally allow for more seamless UDG persistence compared to L3-connected deployments where the client might roam across subnet boundaries managed by different gateways.  

Re-authentication:Seamless roaming mechanisms aim to minimize full re-authentications during roaming events.  

Analysis of Options:

A: Full re-authentication after re-association on L3-connected gateways might occur in some scenarios but contradicts the goal of seamless roaming.  

B: States the UDG remains fixed on L2-connected but not on L3-connected gateways. This aligns with the architectural differences in handling mobility across L2 vs L3 boundaries within a cluster.  

C: Incorrect. CoA is generally sent to the RADIUS client/proxy (the Gateway Cluster), not always directly to the APs.  

D: Correct. Gateways commonly act as a RADIUS proxy, while the AP remains the authenticator handling EAPoL with the client.  

E: Incorrect. The RADIUS proxy function is not limited to only Tunnel and Bridged modes.  

Conclusion:Options B and D accurately describe common characteristics of 802.1X operation within an AOS-10 Gateway Cluster architecture.