AOS-CX Fundamentals and Configuration Management
AOS-CX is a Linux-based network OS with a modular, database-driven design. Candidates must be fluent in the operational model: candidate configuration versus running configuration, checkpoint and rollback, configuration profiles, and the REST API/CLI duality. The candidate/running distinction is the single most tested idea - changes are staged and only take effect on commit, and uncommitted changes can be discarded.
Know the CLI hierarchy: user exec, privileged exec (enable), global config, and context-specific submodes. Understand show running-config versus show startup-config, and how write memory/copy running-config startup-config persists configuration. Be comfortable with user roles and remote authentication (RADIUS/TACACS+), SSH-only management, and the REST API for automation.
Traps that appear in questions:
- Assuming a typed command is immediately active - without
commitit is only candidate configuration. - Confusing checkpoints (full config snapshots you can roll back to) with the candidate buffer.
- Forgetting that some changes (e.g., management interface addressing) can disrupt your session; use checkpoints first.
- Mixing up AOS-CX syntax with AOS-Switch or Cisco IOS equivalents.
Worked example / rule of thumb: before any risky change, run checkpoint pre-change, make edits, show configuration to review the candidate diff, then commit. If the change breaks reachability, checkpoint rollback pre-change restores the prior state. Treat checkpoint-then-commit as muscle memory; exam items often describe an outage and ask which mechanism recovers fastest - the answer is usually checkpoint rollback, not manual re-typing.
Also review firmware/software upgrade workflow and the dual-partition boot concept.