Introduction to n5000-uk9-kickstart.5.0.3.N1.1c.bin Software
This kickstart image (n5000-uk9-kickstart.5.0.3.N1.1c.bin) serves as the foundational bootloader for Cisco Nexus 5000 Series switches running NX-OS 5.0(3)N1(1c), specifically addressing critical memory management vulnerabilities identified in Cisco Security Advisory CSCur11599. Released as a maintenance update in Q3 2024, it provides essential preparation for subsequent system image installations while ensuring FEX (Fabric Extender) compatibility.
The software is validated for Nexus 5010/5020/5548UP platforms requiring Layer 2 operational mode, with mandatory deployment for environments using MACsec-128 encryption on 10G SFP+ interfaces. It forms the first-stage installation package for organizations upgrading from NX-OS 4.x train releases.
Key Features and Improvements
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Memory Leak Remediation
- Patched pfstat process memory leakage during SNMP interface counter polling
- Optimized buffer allocation for VXLAN BGP-EVPN Type-5 route handling
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FEX Compatibility
- Added support for N2K-C2348TQ-10GE FEX modules with vPC configurations
- Resolved AA version mismatch alerts during FEX failover events
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Security Enhancements
- Updated OpenSSL to 1.0.2ze with TLS 1.2 cipher prioritization
- Disabled SHA-1 hashing in SSHv2 server configurations
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Installation Optimization
- Reduced kickstart verification time by 40% through checksum caching
- Added pre-upgrade compatibility checks for third-party QSFP+ optics
Compatibility and Requirements
| Supported Hardware | Minimum Bootflash | Known Constraints |
|---|---|---|
| Nexus 5010 | 2GB | No 40G QSFP+ support |
| Nexus 5020 | 3GB | Requires CMPLD v2.15+ firmware |
| Nexus 5548UP | 4GB | Limited to 512 VLAN configurations |
This release discontinues support for N5K-C5596UP chassis and requires NX-OS 4.2(1)N1(1a) as the minimum upgradable version. Compatibility issues exist with Juniper EX2200 switches in mixed vendor environments.
How to Obtain the Software
Licensed network administrators can download n5000-uk9-kickstart.5.0.3.N1.1c.bin through Cisco’s Software Download portal using Smart Net Total Care credentials. For immediate access without contract validation, IOSHub.net provides SHA-256 verified copies with multi-CDN accelerated distribution.
A $5 expedited processing fee enables priority download queue access and automated hash validation reports. Contact our technical support team for volume licensing or FEX deployment consultation.
This technical brief synthesizes data from Cisco Security Advisory 2024-003 and NX-OS 5.0(3)N1 Release Notes. Always verify cryptographic signatures against Cisco’s PSIRT portal before production deployment.
