It’s important to clarify from the outset:
; it runs the actual code. When a command fails or a route doesn't propagate, it’s usually because of your config, not a software limitation. A Quick Word of Caution i86bilinuxl3adventerprisek9m21573may2018bin portable
While not 100% Cisco IOS syntax, these are production-grade, portable (Docker/VM), and legally free. Overview ; it runs the actual code
Unpacking the i86bilinuxl3adventerprisek9-mz.157-3.May2018.bin – A Portable Take on IOSv for GNS3/EVE-NG it’s usually because of your config