C3745-adventerprisek9-mz.124-25d.bin !link! -

The 12.4(25d) version, while not the latest, is a mature and stable release that is highly predictable.

Cisco IOS images are copyrighted software. Using them outside of a valid support contract for a physical device is generally a violation of Cisco's licensing terms. You cannot download an IOS from Cisco.com without an active support contract. c3745-adventerprisek9-mz.124-25d.bin

While newer virtual platforms like Cisco VIRL/CML (using IOSv, IOS-XEv, and XRv) have become mainstream, the legacy 3745 image holds unique advantages: Legacy 3745 IOS ( 12.4-25d ) Modern Virtual IOS ( IOSv / IOS-XEv ) Extremely low (~64MB to 128MB RAM per instance) High (512MB to 4GB+ RAM per instance) Boot Time Near-instantaneous (under 15 seconds) Moderate to Slow (1 to 5+ minutes) Stability in GNS3 Flawless due to decades of optimization Excellent, but resource-heavy Licensing Requires entitlement to legacy Cisco software Requires Cisco CML subscription The Critical Step: Idle-PC Value Tuning The 12