Hardware-based encryption for hop-by-hop security.
Understanding Cisco IOS XE Release 03.11.05.E (15.2(7)E5) for Catalyst 4500E
This is a "Universal" image containing all features (Base, IP Base, Enterprise Services). The "k9" indicates it supports strong payload encryption (triple DES/AES). cat4500e-universalk9.spa.03.11.05.e.152-7.e5.bin
The universalk9 designation allows for the configuration of:
This long-form identifier describes a critical maintenance release within the Cisco IOS XE 3.11.xE train. Decoding the Filename Hardware-based encryption for hop-by-hop security
Designed specifically for the Catalyst 4500E chassis (such as the 4503-E, 4506-E, 4507R+E, and 4510R+E).
Indicates a digitally signed software package, ensuring the firmware hasn't been tampered with. 03.11.05.E: This is the IOS XE version. The universalk9 designation allows for the configuration of:
As the Catalyst 4500E series transitions toward the end of its lifecycle in favor of the Catalyst 9400 series, many organizations are looking for a "final resting version"—a stable software release to run until the hardware is retired. Release is often chosen because it addresses long-standing vulnerabilities (like PSIRTs related to OpenSSL) found in earlier 3.6 or 3.8 builds.
Typically used with Supervisor 7-E, 7L-E, 8-E, and 8L-E.