End-of-Life (EOL) Notice: The Cisco Nexus 9300-EX Series has officially reached its End-of-Sale (EOS) and End-of-Life (EOL) milestones. This guide is provided strictly for existing network maintenance, refurbished market purchases, and migration planning. For new data center deployments, presales engineers MUST quote the current-generation Nexus 9300-FX3, GX, or GX2 Series.

1. Product Overview & Typical Business Use Cases

The Cisco Nexus 9300-EX Series represents Cisco’s first-generation Cloud Scale ASIC platform. Built for top-of-rack (ToR) and middle-of-row (MoR) deployments in enterprise data centers, these switches support both Cisco ACI (Application Centric Infrastructure) and standalone NX-OS modes. They were designed to bridge the gap between classic 10G infrastructures and modern 25G/100G data centers.

Typical Deployment Scenarios (Brownfield & Maintenance)

Deployment ScenarioArchitectural RoleTechnical Rationale
25G Virtualization Compute AccessTop-of-Rack (ToR) LeafDirect connection to VMware vSphere, Hyper-V, or Nutanix HCI nodes utilizing 10G or 25G DAC/fiber. Provides low-latency east-west traffic switching.
VXLAN EVPN Leaf NodesVTEP EndpointActs as the encapsulation/decapsulation boundary in a classic BGP EVPN spine-leaf topology, isolating tenant traffic in medium-scale data centers.
Legacy ACI MigrationsACI Fabric LeafServing as an ACI Leaf in aging fabrics managed by APIC controllers. Often maintained until budget allows for a complete fabric refresh to FX3 hardware.
Storage Area Networks (IP-SAN)iSCSI / NVMe-oF AccessProviding lossless Ethernet capabilities (PFC, ECN) for moderate IP storage workloads, though newer platforms with deeper buffers are preferred for heavy AI/ML storage.

2. Architecture & Form Factors

The Nexus 9300-EX utilizes a 1RU, non-blocking architecture powered by Cisco’s Cloud Scale ASIC. The platform operates under a strictly bifurcated software model: it must boot in either ACI mode or NX-OS mode.

Hardware Architecture Capabilities

Architectural FeatureEX Series CapabilityEngineering Boundary & Limitation
Operating System ModeDual-boot (NX-OS or ACI)Requires a complete image wipe and reboot to switch modes. Not dynamically interchangeable.
ASIC Technology1st Gen Cisco Cloud ScaleOptimized for 10/25G access and 100G uplinks. Lacks the advanced telemetry capabilities of modern GX ASICs.
MACsec EncryptionHighly ConstrainedThe EX series has severe hardware limitations regarding MACsec line-rate encryption. Environments requiring pervasive DCI encryption should migrate to FX3.
Telemetry & Flow DataTetration / Nexus DashboardSupports hardware-based flow streaming, but ASIC export buffers are small, risking flow drop under massive DDoS or microburst conditions.
Fibre Channel over EthernetFCoE NPV ModeSupported on specific ports (e.g., first 16 ports), but requires careful port-map validation and SAN licensing.

Software Baselines & Golden Releases

For stability in legacy environments, engineering teams should standardize on the Cisco recommended “Golden Release” for NX-OS. For the EX platform, the 9.3(10) or 10.2(x) long-lived trains are heavily vetted. Upgrades in ACI mode MUST strictly follow the APIC compatibility matrix.

3. Performance & Scaling

Data center switches must be sized according to exact packet processing limits and buffer depth, not just interface speed.

System Performance Metrics

Performance MetricFlagship N9K-C93180YC-EXN9K-C93108TC-EX (Copper)
Maximum Switching Capacity3.6 Tbps2.16 Tbps
Forwarding Rate (IPv4)Up to 2.6 Billion packets/sec (Bpps)Up to 1.7 Billion packets/sec (Bpps)
System Buffer Depth40 MB Shared Buffer40 MB Shared Buffer
MAC Address TableUp to 256,000 entriesUp to 256,000 entries
IPv4 Host RoutesUp to 128,000Up to 128,000
IPv4 Longest Prefix Match (LPM)Up to 8,000Up to 8,000
Multicast RoutesUp to 32,000Up to 32,000

Engineering Warning: The 40 MB shared buffer is adequate for standard enterprise virtualization. However, for high-frequency trading (HFT), deep-learning AI clusters, or massive Hadoop analytics environments subject to extreme microbursts, 40 MB will result in tail-drops. Presales designs for such environments must utilize Nexus 9000 switches with deep buffers (e.g., Nexus 9236C or modern equivalents).

4. Power & Typical Consumption

Power provisioning in the data center must be highly precise to avoid tripping PDU breakers or overwhelming CRAC (Computer Room Air Conditioning) units.

Exact Power Consumption (Flagship N9K-C93180YC-EX)

Load ConditionExact Power DrawHeat Dissipation (BTU/hr)
Typical Operating Power210 Watts (50% traffic load, SR optics)~716 BTU/hr
Maximum Power Draw460 Watts (100% load, LR/DAC optics, 100% fans)~1,569 BTU/hr

Power Supply Units (PSUs) & Airflow

The chassis accommodates two PSUs for 1+1 redundancy.

PSU Part NumberRated OutputInput TypeAirflow DirectionApplication
NXA-PAC-650W-PI650WAC (100-240V)Port-Side Intake (PI)Standard Cold Aisle to Hot Aisle
NXA-PAC-650W-PE650WAC (100-240V)Port-Side Exhaust (PE)Reversed Airflow (Hot Aisle to Cold)
NXA-PDC-930W-PI930WDC (-48V to -60V)Port-Side Intake (PI)Telco/Carrier environments

Thermal Red Line: You MUST ensure that PSU airflow (PI/PE) matches the Fan module airflow (PI/PE). Mismatched airflow components will cause the switch to trigger an immediate hardware thermal shutdown within 2 minutes of boot to prevent ASIC meltdown.

5. Uplinks, Modules & Optics

The Nexus 9300-EX features fixed uplinks; there are no modular expansion slots.

Port Configuration Matrix

Chassis ModelAccess Ports (Downlinks)Spine UplinksBreakout Capability
93180YC-EX48 x 1G/10G/25G SFP286 x 40G/100G QSFP28Uplinks support 4x10G and 4x25G
93108TC-EX48 x 100M/1G/10G BASE-T (RJ45)6 x 40G/100G QSFP28Uplinks support 4x10G and 4x25G
93180LC-EX32 x 40G/50G QSFP+Configurable (up to 18x100G)Extreme high-density leaf; requires strict port-mapping validation

Optic & Transceiver Design Rules

  • 25G Server Access: SFP28 ports natively support 1G (GLC-TE/SX), 10G (SFP-10G-SR), and 25G (SFP-25G-SR-S) speeds without requiring physical adapters.
  • Twinax DAC Cables: For intra-rack server connections, 10G (SFP-H10GB-CUxM) and 25G (SFP-H25G-CUxM) passive copper cables are fully supported and represent a significant CapEx saving over optical transceivers.
  • 100G Breakout Architecture: The QSFP28 uplink ports support optical splitters (e.g., QSFP-100G-SR4 to 4x SFP-25G-SR) or breakout DACs. This allows a spine port to fan out directly to compute nodes if the switch is repurposed from a ToR Leaf to a localized aggregation point.

6. Comprehensive SKUs

When sourcing refurbished hardware or verifying existing inventory, exact part numbers are critical.

Exact Part NumberDescription & Port LayoutSoftware Focus
N9K-C93180YC-EXNexus 9300 with 48p 10/25G SFP28 and 6p 100G QSFP28Primary Flagship Fiber ToR
N9K-C93108TC-EXNexus 9300 with 48p 10G BASE-T (Copper) and 6p 100G QSFP28Legacy Copper Server ToR
N9K-C93180LC-EXNexus 9300 with 32p 40/50G QSFP+ (Configurable up to 18p 100G)High-Density Migration Leaf
NXA-FAN-30CFM-BNexus Fan, Port-Side Intake (Blue Latch)Matching PI Power Supplies
NXA-FAN-30CFM-FNexus Fan, Port-Side Exhaust (Burgundy Latch)Matching PE Power Supplies

7. Environmental Specs & Warranty

Physical footprint planning is critical for rack elevation and weight distribution limits in legacy colocation facilities. The parameters below are hard engineering facts for the N9K-C93180YC-EX.

Environmental MetricExact Specification
Rack Units (RU)1 RU
Exact Depth19.6 inches (49.8 cm)
Exact Width17.3 inches (43.9 cm)
Exact Height1.72 inches (4.4 cm)
Installed Weight17.2 lbs (7.8 kg) (Fully populated with 2 PSUs and 4 Fans)
Operating Temperature32°F to 104°F (0°C to 40°C) at sea level
Acoustic Noise48.5 dBA at 40% fan speed; 73.9 dBA at 100% fan speed

Warranty and Maintenance Support Boundaries

Because the EX platform is End-of-Life, the standard 1-Year Limited Hardware Warranty has expired for virtually all original purchasers.

  • Hardware Replacement: For ongoing operations, presales and maintenance engineers MUST verify the availability of refurbished spares (NBD replacement is no longer guaranteed directly from Cisco uncontracted).
  • Software Updates: Active Cisco Smart Net Total Care (SNTC) contracts covering the exact chassis serial numbers are strictly required to obtain TAC support and to legally download security patches (NX-OS) until the published Last Date of Support (LDoS).

8. Licensing Constraints

When managing EX series switches, software licensing is heavily dependent on the NX-OS release and whether the switch is in ACI mode.

  • DCN Essentials vs. Advantage: Basic BGP/OSPF and VXLAN EVPN require DCN Advantage licensing. Do not assume segment routing or Nexus Dashboard Insights entitlement from a base license tier alone.
  • Smart Licensing: Smart Licensing Using Policy (SLUP) behavior depends on upgrading the NX-OS release to 9.3(6) or higher. Standalone traditional RTU (Right to Use) licensing is deprecated in modern builds.