Cisco ACI - Node states - Unknown vs discovering vs undiscovered vs Unsupported vs decommissioned vs inactive Vs active

 In Cisco ACI, node states describe the status of a fabric node (like a leaf or spine switch) in relation to the APIC controller and the overall fabric. Here's a breakdown of the common node states you mentioned:

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🔹 Active

• The node is fully discovered, registered, and operational in the fabric.
• It is participating in policy enforcement and forwarding traffic.

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🔹 Inactive

• The node is known to the APIC but is not currently participating in the fabric.
• This could be due to administrative shutdown or connectivity issues.

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🔹 Discovering

• The APIC has detected the node and is in the process of gathering its information.
• This is a transitional state before becoming active.

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🔹 Undiscovered

• The node is not yet detected by the APIC.
• It may be powered off, disconnected, or not properly cabled.

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🔹 Unknown

• The APIC cannot determine the state of the node.
• This could be due to communication failure or misconfiguration.

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🔹 Unsupported

• The node is running a software version or hardware type that is not compatible with the current ACI fabric.
• It cannot be managed or used until upgraded or replaced.

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🔹 Decommissioned

• The node has been intentionally removed from the fabric.
• It no longer participates in any fabric operations and is not expected to return unless re-commissioned.

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🧠 Summary Table

Node State	Description	Common Causes
Active	Node is fully discovered and operational within the fabric.	Successful discovery, proper cabling, compatible firmware.
Inactive	Node is known to APIC but not participating in the fabric.	Admin shutdown, link issues, or configuration mismatch.
Discovering	Node is in the process of being onboarded into the fabric.	Initial connection, waiting for LLDP adjacency or infra VLAN.
Undiscovered	Node is not detected by APIC.	Cabling issues, powered off, wrong port type, or missing infra VLAN.
Unknown	APIC cannot determine the node’s state.	Communication failure, misconfigured switch, or APIC database inconsistency.
Unsupported	Node hardware or software is incompatible with the current ACI fabric.	Outdated firmware, non-ACI image, or unsupported model.
Decommissioned	Node has been intentionally removed from the fabric.	Manual decommissioning via APIC or CLI.