APIC orientation
How to read the APIC UI: tenants, fabric, inventory, faults, health, and the managed object tree.
APIC is not just a switch manager. It is the controller that stores the policy model for the fabric. The simulator gives you the same basic navigation pattern you will use on a real fabric.
The areas to learn first
Start with these sections:
| Area | What to look for |
|---|---|
| Tenants | Application policy: VRFs, bridge domains, app profiles, EPGs, contracts |
| Fabric | Switch inventory, fabric membership, health, faults |
| System | Controller health, users, AAA, certificates, system settings |
| Operations | Faults, events, audit logs, endpoint learning |
| Admin | Authentication, RBAC, export/import, firmware-style administration |
For learning, spend most of your time in Tenants, then use Fabric and Operations to understand what APIC thinks is happening.
Faults matter
ACI exposes many errors as faults. This is one of the most useful habits to build early: after every policy change, check whether APIC raised a fault.
Examples:
- A domain is missing from an EPG.
- A VLAN is not in the right pool.
- A static path points to the wrong interface.
- A contract exists but is not applied in the expected direction.
- A policy object exists but is not attached to anything useful.
In a real fabric, faults are often faster than guessing from CLI output. The simulator is a safe place to learn how APIC describes broken intent.
The object tree
ACI is a managed object system. The GUI is just one view of it. Behind every screen is a tree of objects with distinguished names.
Useful examples:
| Object | Meaning |
|---|---|
fvTenant | Tenant |
fvCtx | VRF |
fvBD | Bridge domain |
fvAp | Application profile |
fvAEPg | Endpoint group |
vzBrCP | Contract |
vzFilter | Filter |
When you understand the object tree, automation becomes less mysterious. Terraform, Ansible, and direct REST calls are all creating or reading these same objects.
A good first tour
- Log in to APIC.
- Open Tenants and inspect the built-in tenants:
common,infra, andmgmt. - Open Fabric and inspect the simulated nodes.
- Open Operations and review faults and events.
- Use the search box to find a tenant, bridge domain, or contract.
- Open the API inspector if your APIC version exposes it, then make a simple GUI change and observe the generated API call.
The goal is not to memorize the UI. The goal is to see that every GUI action changes an object in the APIC model.