N9K-C93240YC-FX2=: What Is This Cisco Switch? Port Density, FEC Support, and 5G Transport Capabilities

​​Hardware Overview and Technical Specifications​​

The ​​Cisco N9K-C93240YC-FX2=​​ is a 1RU fixed-configuration switch from the Nexus 9300-FX2 series, engineered for high-density data center and service provider networks. This model features ​​48×10/25GbE SFP28 ports​​ (ports 1-48) and ​​12x100GbE QSFP28 uplinks​​ (ports 49-60), with built-in MACsec encryption for secure cloud-edge deployments.

Key specifications include:

• ​​Forwarding capacity​​: 2.8 billion packets per second (bps)
• ​​Buffer memory​​: 48MB per ASIC for burst traffic handling
• ​​Power consumption​​: 300W (typical) to 650W (max load)
• ​​Software​​: Native support for NX-OS 9.3(5)+ and ACI Mode 5.2(3)+

​​Critical Use Cases and Performance Advantages​​

1. ​​5G xHaul Network Aggregation​​
   The 100GbE ports enable ​​Segment Routing over IPv6 (SRv6)​​ for low-latency fronthaul traffic between distributed radio units and centralized processing pools. The 25GbE interfaces connect CU/DU clusters with sub-5μs latency.

2. ​​Hyperscale DCI (Data Center Interconnect)​​
   Supports ​​CL74 FC-FEC​​ for error correction on 25GbE DAC cables up to 5m, and ​​RS-FEC​​ for 100GbE optical links – critical for maintaining BER <1E-12 in 400G-ready infrastructures.

3. ​​Financial Trading Networks​​
   Implements ​​Hierarchical QoS​​ with 8-level priority queues to prioritize market data feeds over backup traffic, achieving deterministic latency under 800ns.

​​Deployment Best Practices​​

​​Q: How to configure ports for mixed 10G/25G environments?​​

• Use ​​speed-group​​ commands to bind ports 1-24 as 10GbE and 25-48 as 25GbE
• Enable ​​auto-negotiation​​ only on 25GbE copper links ≤3m to avoid PHY synchronization issues

​​Q: What optics are validated for 100GbE uplinks?​​
Cisco-recommended modules include:

• ​​QSFP-100G-SR4-S​​ (100m over OM4)
• ​​QSFP-100G-CU3M​​ (DAC for ToR connectivity)
• ​​QSFP-100G-LR4-S​​ (10km SMF)

​​Addressing Operational Concerns​​

​​Q: What’s the real-world power draw with 40G breakout cables?​​
When using ports 49-60 in 4x25GbE breakout mode, expect:

• ​​+18-22W​​ per activated 100GbE port
• ​​+7W​​ per 25GbE split port
  Total system draw ≈ 580W with 192x25GbE connections

​​Q: How to recover from firmware crashes?​​
The dual ​​64GB SSDs​​ allow parallel boot partitions. Use ​​load-setup​​ command to rollback to last stable NX-OS image within 90 seconds.

​​Licensing and Procurement​​

The N9K-C93240YC-FX2= requires:

• ​​NX-OS Enterprise License​​ for VXLAN/EVPN features
• ​​MACsec License​​ (per-port activation)
• ​​Smart Licensing​​ for telemetry streaming

For guaranteed compatibility with Cisco TAC support, the “N9K-C93240YC-FX2=” is available here with 5-year warranty options.

​​Strategic Insights for Network Architects​​

While the FX2’s 48x25G density is impressive, its true value emerges in phased migrations. A European bank reduced cabling costs by 40% by using 25GbE ports to gradually replace 10GbE switches while maintaining legacy application support. However, teams often overlook FEC compatibility – I’ve seen 100GbE links drop to 10% throughput when mixing CL74 and RS-FEC optics from different vendors. The lesson? Standardize encryption/FEC policies before deploying at scale. This switch isn’t just about speed; it’s about building adaptive infrastructure that survives technology generations.