Cisco QDD-400-CU2.5M 400G Passive Cable, 2.5 m | DAC, QSFP-DD — QDD-400-CU2.5M

Maintain 400G connectivity where short reach matters most. Cisco QDD-400-CU2.5M is a 2.5 m passive copper cable designed for direct attach deployments that need high throughput with minimal complexity. By removing active electronics from the link, it helps reduce power consumption and thermal load while preserving the deterministic behavior infrastructure teams expect in tightly packed racks. This cable is a practical fit for top-of-rack and adjacent-rack interconnects where fiber transceivers would add unnecessary cost and management overhead. The passive design keeps the signal path simple, which is exactly what you want for short distances inside modern data center rows. For teams standardizing on 400G infrastructure, it offers a clean way to connect compatible Cisco platforms with the physical simplicity of copper and the bandwidth profile required for current-generation aggregation and spine layers. Choose this cable when you need a short, purpose-built 400G link that aligns with high-density rack design and disciplined cabling practices. It is the kind of component that earns its place in production by doing one job well: carrying 400G traffic reliably over a short span with no extra optics to manage. Ideal For Connect adjacent spine and leaf switches in a 400G fabric Link top-of-rack switches to nearby aggregation equipment Attach compatible servers or appliances in high-density racks Replace short fiber runs where passive copper is sufficient Why This Product 1 Passive copper avoids the power and heat of active optics 2 2.5 m length suits adjacent-rack 400G links 3 QSFP-DD direct attach format simplifies deployment 4 Purpose-built for short-reach Ethernet interconnects