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 Fabric Secure Mode Overview Fabric Secure Mode is a security feature in Cisco ACI that safeguards the infrastructure from unauthorized additions. It ensures that only verified switches and APIC controllers can join the fabric, even if someone has physical access to the equipment. Starting from release 1.2(1x), Cisco ACI performs a validation check during installation or…

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  Aspect Stateful Reload Stateless Reload Definition Reload where process state is preserved using checkpoints Reload where process starts fresh without any prior state State Preservation Yes – runtime state is saved to Persistent Storage Services (PSS) No – process is restarted without retaining previous state Recovery Speed Faster – resumes from last known state…

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    Undiscovered: You’ve manually added a node ID in APIC. The switch is not yet connected or powered on. Could be due to cabling issues or incorrect port configuration.   Unknown: The switch is physically connected and sending LLDP packets. APIC detects it but doesn’t have a matching Node ID policy. You need to…

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 🔷 What is a Contract Preferred Group in ACI? In Cisco ACI, Endpoint Groups (EPGs) typically require contracts to communicate with each other. This follows the “allow list” model, where communication is explicitly permitted only if a contract exists. The Preferred Group (PG) feature simplifies this by allowing certain EPGs within the same VRF to communicate freely without contracts. ✅ Key Concepts Term Description Included…

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 To replace a Cisco ACI leaf switch, follow these step-by-step instructions to ensure a smooth transition without disrupting your fabric: 🛠️ Preparation Document the existing switch details: POD ID Node ID Node Name Serial Number  Ensure the replacement switch is in ACI mode: Connect via console and run show version. If in NX-OS mode, convert to ACI mode using…

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   Common Causes of “Unknown” Leaf State Certificate Issues: The leaf might not be presenting a valid certificate chain to the APIC, which prevents proper SSL handshake and authentication. LLDP Mismatch or Failure: ACI relies on LLDP (Link Layer Discovery Protocol) for fabric discovery. If LLDP info isn’t exchanged correctly between APIC and leaf, discovery…

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 In Cisco ACI (Application Centric Infrastructure), Contracts are a key component of the policy model, used to define how endpoints (EPGs) communicate with each other. Within contracts, the terms Labels, Filters, Aliases, and Subjects each play distinct roles. Here’s a breakdown of each: 🔹 1. Filters Purpose: Define the actual traffic (protocols, ports) that is allowed or denied. Details: Filters are composed of entries specifying…

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  Feature Aliases Labels Purpose Abstract reference to filters for modular contract design Tagging mechanism for categorization and automation Used In Subjects within Contracts EPGs, Contracts, Bridge Domains, Application Profiles, etc. Functionality Indirectly reference filters to simplify reuse Group and organize objects; used in automation workflows Visibility Internal, technical use Administrative, visible in UI and…

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🟢 Standard Modules These are full-featured and support everything (including FCoE, OTN, etc.). SFP-10G-SR: Short range (up to 400m on multimode fiber) SFP-10G-LR: Long range (up to 10km on single-mode fiber) SFP-10G-ER: Extended range (up to 40km) SFP-10G-ZR: Ultra-long range (up to 80km) ✅ Supports all protocols ✅ TAA compliant ✅ Good for enterprise/data center use 🔵 S-Class Modules…

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  Aspect Taboo Contract vzAny Contract Purpose Used to explicitly deny certain types of traffic for an EPG Used to apply contracts to all EPGs within a VRF in a simplified manner Functionality Acts as a deny filter for specific traffic (e.g., block port 80 or 23) Acts as a wildcard to apply contracts to…

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