The exhibit illustrates a high-availability design involving an AOS-CX 8325 VSX core pair and an AOS-CX 6300M VSF access stack. To determine the necessary change, we must evaluate the bandwidth relationship between the Inter-Switch Link (ISL) and the Access Uplinks.
VSX ISL Bandwidth Best Practice: A fundamental rule in Aruba VSX design is that the ISL (Inter-Switch Link) bandwidth should be equal to or greater than the bandwidth of the highest-speed uplink or the aggregate bandwidth of the downstream access connections. This ensures that in the event of a link failure (where traffic must traverse the ISL to reach its destination), the ISL does not become a bottleneck, causing packet loss or increased latency.
Analyzing the Current Topology:
The Access Uplinks from the CX 6300 stack to the CX 8325 core are utilizing 25GBase-SR (25 Gbps) connections.
The VSX ISL (ports 1/1/47 and 1/1/48 on the CX 8325s) is currently configured with 10GBase-SR (10 Gbps) optics.
This creates a " bottleneck " scenario where the core synchronization and failover path (10G) is significantly slower than the access path (25G).
Hardware Capabilities:
The AOS-CX 8325-48Y8C features 48 ports that support SFP/SFP+/SFP28 (1G/10G/25G).
Ports 1/1/47 and 1/1/48 are SFP28 capable. To adhere to best practices and match the 25G speed of the downstream 6300 uplinks, these ISL ports must be upgraded from 10G (SFP+) to 25G (SFP28).
Evaluating Other Options:
Option B is incorrect because the CX 8325 does not support SFP56 (50G) transceivers; SFP56 is typically found on the CX 6300/6400 series.
Option C is incorrect because the CX 6300M does not have QSFP28 (100G) ports; it uses SFP56 for its high-speed uplinks.
Option D is incorrect because the 6300 is already using 25G. While it could support SFP56, upgrading the access side to 50G while leaving the Core ISL at 10G would only exacerbate the bandwidth mismatch.
Therefore, the most critical architectural correction is upgrading the 8325 ISL ports to SFP28 to ensure the ISL bandwidth matches the 25G access uplinks.
