Run the fixpermissions script via SSH. Double-check that your iourc text file contains the correct MD5-based key generated for your specific virtual machine host name. 2. Microcode/Alignment Errors in the Console
, it does not support full Layer 2 switching functionality (like VLAN configuration or SVIs); for those tasks, a separate L2 image (e.g.,
| Component | Meaning | | :--- | :--- | | | Architecture: Intel x86 (32-bit) Binary. This runs on standard x86 CPUs, not Cisco’s proprietary hardware. | | linuxl3 | Host OS & Function: Runs on Linux and provides Layer 3 routing features. (Contrast with linuxl2 for switching). | | adventerprisek9 | Feature Set: Advanced Enterprise with K9 (Cryptographic support for VPNs, SSH, IPSec). | | m2 | Platform/Driver Set: Typically indicates a modular image or specific virtual driver interface for IOL. | | 157-3.may.2018 | Version: IOS version 15.7(3), compiled in May 2018. | | .bin | Binary executable – the raw machine code image. | i86bi linuxl3-adventerprisek9-m2 157 3 may 2018.bin
IOU images are extremely lightweight compared to full virtual machine images (like CSR1000v), allowing you to run hundreds of nodes on standard hardware. Common Use Cases CCNP/CCIE Labbing:
Unlike Cisco VIRL or CML’s standard vIOS routers, this IOL image consumes significantly less RAM and CPU. A single instance typically uses 128–256 MB of RAM, allowing a user to run 50+ nodes on a modest server. Run the fixpermissions script via SSH
: These images are technically Cisco internal tools and require a specific license file (typically named iourc ) to function within emulators.
chmod +x /opt/unetlab/addons/iol/bin/i86bi-linuxl3-adventerprisek9-m2.157-3.may.2018.bin /opt/unetlab/wrappers/unl_wrapper -a fixpermissions Microcode/Alignment Errors in the Console , it does
At its core, this .bin file is a compiled specifically to run as a user-space process on a Linux host. Unlike physical router firmware that interacts directly with ASICs, this image emulates the control plane of a Cisco Layer 3 switch or router using a technology often called IOU (IOS on Unix) or IOL (IOS on Linux) .
| Error Message | Likely Cause | Fix | | :--- | :--- | :--- | | IOU with no license | Missing or invalid iourc file | Verify license hash and file path. | | error while loading shared libraries: libc.so.6 | Missing 32-bit libs | sudo dpkg --add-architecture i386 && apt update && apt install libc6:i386 | | Image version mismatch | Wrong wrapper script | Use i86bi_L3 wrapper from Eve-NG, not a generic IOL. | | CPU 0: can’t allocate memory | Host RAM exhaustion | Reduce node count or add swap. |
Earlier versions of the 15.x L3 branch (specifically version 15.5(2)T) contain an internal loop anomaly that causes the interactive terminal console to permanently freeze after several hours of continuous uptime. The May 2018 M2 compilation thoroughly resolves this bug, ensuring that long-running network simulations remain interactive for days. Environment Setup & Integration