Access vs Aggregation: N9K-C9372TX-E vs N9K-C9348D-GX2A, the "Scene Battle" of High-Density PoE and Versatile Convergence

Aug 08 , 2025 5

1. Access vs Aggregation: N9K-C9372TX-E vs N9K-C9348D-GX2A, the "Scene Battle" of High-Density PoE and Versatile Convergence

In Cisco’s Nexus 9300 family, the N9K-C9372TX-E (hereinafter "9372TX") and N9K-C9348D-GX2A (hereinafter "9348D") are like "same-generation siblings with distinct roles"—the former a "high-density PoE specialist" for access layers, the latter a "versatile all-rounder" for aggregation. This article breaks down their real-world differences across 15 dimensions to help you match them to your needs.

2. Performance Strengths: "Multitool" of Access vs "All-Rounder" of Aggregation

Despite belonging to the same 9300 series, their roles drive significant hardware differences:

• Processing Speed:

• 9372TX: Fixed configuration with simplified ASIC, 100Gbps per-slot bandwidth (48×25G ports + 4×100G uplinks), 1.6Tbps total capacity; VXLAN latency 0.8μs, ideal for small-to-medium traffic (office terminals, IP cameras).

• 9348D: Modular design with Cloud Scale ASIC (CSA), 400Gbps per-slot bandwidth (48×10G ports + 4×400G expansion slots), 25.6Tbps total capacity (fully populated); VXLAN latency 0.5μs, line-rate forwarding for data center aggregation.

• Running Memory:

• 9372TX: 16GB DDR3 (non-expandable), 800,000 flow entries, suited for small traffic;

• 9348D: 32GB DDR4 (expandable to 256GB), 2 million ACL rules, supporting complex policies.

• Storage Capacity:

• 9372TX: No onboard storage, relies on USB2.0 (max 500GB) for OS, slower boot (20% delay);

• 9348D: 16GB eMMC (expandable to 64GB), USB3.0 external drives (max 2TB) for logs/system images, ideal for local log retention.

3. Feature Sets: "Vertical Tools" of Access vs "Omnipotent Platforms" of Aggregation

• 9372TX:

• Fixed 48×25G SFP28 + 4×100G QSFP28 uplinks, optimized for "high-density access";

• Native PoE++ (30W/port, 720W max), powering APs, phones, and cameras via one cable;

• Basic L2 features (VLAN, STP), no hardware encryption/QoS, suited for simple "endpoint-access" networks.

• 9348D:

• Modular 48×10G SFP+ + 4×400G QSFP-DD slots (supports 100G/200G/400G optics);

• Deep integration with ACI, EVPN-VXLAN, SRv6, and micro-segmentation;

• Hardware encryption (IPSec/SSL) and QoS (1024 queues), ideal for hybrid cloud/multi-branch.

4. Design & Appearance: "Desk-Friendly" vs "Rack Professional"

• 9372TX:

• Dimensions: 1RU × 44mm width × 430mm depth (8kg), front panel with 48×25G SFP28 + 4×100G QSFP28 uplinks (high port density);

• Redundancy: Optional single power supply, no redundant fans (natural cooling), fitting small offices;

• Cooling: Front-to-rear through-flow, silent operation, office-friendly.

• 9348D:

• Dimensions: 2RU × 88mm width × 680mm depth (25kg), front panel with 48×10G SFP+ + 4×400G QSFP-DD uplinks;

• Redundancy: Dual power supplies (1+1) + dual fans (N+1), hot-swappable, requiring 600mm-deep racks;

• Cooling: Bottom-to-top airflow, dependent on data center precision cooling.

5. User Experience: Real Pains of Ops Teams

• 9372TX:

• Strengths: Simplified CLI (70% fewer core-layer commands), "show interface" focused on key metrics (traffic/errors), IT staff proficient in 1 week;

• Pain points: Fixed ports, full replacement needed for new services; no virtualization, VRRP-dependent for redundancy.

• 9348D:

• Strengths: Virtualized clustering (vPC+) simplifies cross-chassis management;

• Pain points: Complex configuration (managing 4 expansion slots), 3+ months learning curve; large logs (50GB/day) risk eMMC overflow.

6. Cost-Effectiveness: Long-Term Investment Math

• Initial Cost: 9372TX ~¥350k (48×25G+4×100G), 9348D ~¥1.2M (48×10G+4×400G slots), nearly 3× price difference.

• Expansion Costs:

• 9372TX: Fixed ports, no expansion costs; 9348D: 400G/800G optics (~¥30k/module), but flexible via slots.

• Maintenance Costs:

• 9372TX: No license fees, ideal for SMBs; 9348D: ACI licenses (~¥80k/year), automated ops (Ansible) reduce labor.

7. Product Advantages: Scenario-Driven "Uniqueness"

• 9372TX: High-density 25G ports (48), PoE++ (720W), simplified ops; perfect for campus access, branch aggregation, and AP/camera deployments.

• 9348D: Ultra-high performance (25.6Tbps), flexible expansion, high reliability; suited for data center aggregation, multi-branch interconnection, and hybrid cloud.

8. System Upgrade: Details Determine Success (Key Section)

Upgrade Scenario: Migrating from NX-OS 9.2(5) to 10.5(2)F (IPv6 SRv6/hardware encryption).

Upgrade Process & Challenges:

1. Pre-Check Phase:

• 9372TX: Verify optics with show interface transceiver vendor, replace non-Cisco modules;

• 9348D: Use show module firmware to sync all modules, force upgrade with software upgrade module <slot> force.

• 9372TX Issue: Third-party optics (non-Cisco 100G QSFP28) fail due to driver incompatibility;

• 9348D Issue: Module firmware mismatches (e.g., a service card at 9.2(3)) cause failures.

• Fixes:

2. Backup & Rollback:

• 9372TX: Use copy running-config scp://admin@192.168.1.100/ for encrypted SSH transfers;

• 9348D: Split backups (configs to TFTP, logs to external server).

• 9372TX Issue: Slow USB2.0 backups (40MB/s) risk interruption;

• 9348D Issue: 16GB eMMC may overflow when backing up configs/logs.

• Fixes:

3. Downtime Control:

• 9372TX: Use NSF/SSO for sub-30-second downtime via active-standby alternation;

• 9348D: Disable non-essential services pre-upgrade (conf t ; no ip dhcp pool test-vlan).

• 9372TX Issue: Full reboots cause 5-10 minute outages for core apps;

• 9348D Issue: Rolling upgrades may disrupt traffic if non-critical services (e.g., test VLAN DHCP) run.

• Fixes:

4. Post-Upgrade Validation:

• 9372TX: Load encryption licenses with license boot module c9300-ipservices, verify with show crypto ipservices;

• 9348D: Add temporary IPv6 routes (ipv6 route 0.0.0.0/0 2001:db8::1) while migrating devices.

• 9372TX Issue: Hardware encryption (IPSec) inactive without license;

• 9348D Issue: Strict IPv6 checks drop unrouted IPv6 traffic, breaking legacy devices.

• Fixes:

9. Product Use Cases

• 9372TX Scenarios:

• Campus access layer: 500+ APs/phones, PoE++ (720W) eliminates extra power cabling;

• Branch aggregation: MPLS VPN with 50ms BFD failover, ensuring ERP stability.

• 9348D Scenarios:

• Data center aggregation: 100k+ VMs, ACI for cross-AZ isolation, hybrid modules (400G line cards + firewalls);

• Multi-branch interconnection: EVPN-VXLAN with hardware IPSec, 25μs latency for real-time trading.

10. Detailed Pros & Cons

11. Conclusion: How to Choose?

• 9372TX: For small-to-medium networks (<5,000 endpoints), cost-sensitive deployments, or PoE-heavy access needs.

• 9348D: For large-scale data center aggregation, multi-branch interconnection, or future expansion plans.