Part of the IOS 15.4 T (Technology) release train, which introduced early features like LISP (Locator/Identifier Separation Protocol) and is widely regarded in the community for its stability during certification studies like CCNP and CCIE. Usage in Virtual Labs Cisco IOL (IOS on Linux) - - EVE-NG
This image is a 32-bit virtual Cisco IOS router that runs as a Linux process (often in QEMU). It is widely used in , CML , GNS3 , and EVE-NG for Layer 3 routing emulation. i86bi-linux-l3-adventerprisek9-15.4.2t.bin