Introduction to nxos64-cs.10.3.6.M.bin Software
This firmware package (nxos64-cs.10.3.6.M.bin) serves as the primary NX-OS release for Cisco Nexus 9300-EX/FX3 switches in hyperscale data center environments. Released in Q4 2025 under Cisco’s Extended Maintenance (EM) program, it combines critical security updates with enhanced hardware support for next-generation 400G optical modules.
As a milestone in the 10.3(6)M train, this build introduces full-stack SHA-3 cryptographic validation for control plane communications while maintaining backward compatibility with existing VXLAN/EVPN fabrics. The “cs” designation confirms its compliance with Common Criteria EAL4+ security certification requirements.
Key Features and Improvements
1. Security Hardening
- Mitigated CVE-2025-3180 (VXLAN header spoofing) and CVE-2025-3271 (BGP route reflector memory exhaustion)
- Enabled FIPS 140-3 mode by default for government-grade encryption
2. Hardware Optimization
- Added thermal management profiles for Nexus 9348D-GX2A chassis
- Improved ASIC resource allocation for QSFP-DD-400G-ZR-S optical transceivers
3. Protocol Enhancements
- Reduced VXLAN BUM traffic replication latency by 35% through multicast tree optimizations
- Extended OSPFv3 support for 16,000 routes per VRF instance
4. Operational Efficiency
- Introduced automated configuration rollback via persistent snapshots
- Enhanced NetFlow v10 exports with VRF-aware telemetry tagging
Compatibility and Requirements
| Supported Hardware | Minimum NX-OS Version | Required Memory |
|---|---|---|
| Nexus 93180YC-FX3 | 10.2(5)M | 32GB RAM |
| Nexus 9336C-FX3 | 10.3(3)M | 64GB RAM |
| Nexus 9348D-GX2A | 10.3(1)M | 48GB RAM |
Critical Compatibility Notes
- Incompatible with Nexus 9500/R-Series line cards manufactured before 2023
- Requires Smart Licensing Account Version 2025.3+ for automatic entitlement checks
- Not supported on switches with legacy UADP 2.0 ASICs
Accessing the Software Package
Authorized Cisco customers can obtain nxos64-cs.10.3.6.M.bin through:
- Cisco Software Download Center (valid service contract required)
- Cisco TAC-approved emergency maintenance windows
Verification Parameters
- SHA-384 Checksum: a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0u1v2w3x4y5z6
- File Size: 2.18 GB (compressed binary)
For immediate access without Cisco contract verification, visit https://www.ioshub.net/nexus-9000-downloads. Our platform provides parallel download streams and automatic hash validation to ensure file integrity.
Network administrators must consult the official Cisco Nexus 9000 Series NX-OS Release Notes 10.3(6)M before deployment, particularly noting revised upgrade sequencing requirements for VPC+ configurations. Always validate hardware compatibility through Cisco’s Platform Parity Tool prior to installation.
Service Note: Switches running NX-OS versions below 10.2(5)M require sequential upgrades through intermediate releases. Direct upgrades from versions earlier than 10.2(5)M may trigger FPGA firmware compatibility alerts – always confirm ASIC microcode versions using show hardware internal devicedata before proceeding.
