C3900-universalk9-mz.spa.157-3.m8.bin ((exclusive)) -

After reload, verify with show version and activate licenses:

| Image | Pros | Cons | |-------|------|------| | (this article) | Stable, well-understood, supports most SPA modules. | No new security patches; EoL; no new hardware support. | | 15.9(3)M10 | Later maintenance train, final IOS Classic release (Dec 2022). | Larger memory footprint; some bugs newly introduced. | | IOS XE 3.16S (if convertible) | Modern architecture, improved security. | Requires different hardware (ISR4k) or software upgrade licence; complex migration. | C3900-universalk9-mz.spa.157-3.m8.bin

Note: universalk9 replaces the older adventerprisek9 image concept. It is more flexible but requires explicit license activation for advanced features. After reload, verify with show version and activate