Cisco ACI L3Out Configuration in Step-by-Step Guide

Configuring an L3Out is often the most intimidating part of a Cisco ACI deployment, because a single missing object can make everything look “correct” while nothing actually routes.

In this 15-minute video walkthrough, I’ll show you the full ACI L3Out configuration workflow in APIC, step by step, to connect your ACI fabric to the external networks. We’ll build it end-to-end in the same order you’d use in a real deployment.

Summary

  • Step 1: Configure an L3 Domain and Access Policies Used in the L3Out.
  • Step 2: Configure the MP-BGP Route Reflectors.
  • Step 3: Create the L3Out Object.
  • Step 4: Create the L3Out Node and Interface Profiles.
  • Step 5: (If Required) Create a Protocol Interface Policy.
  • Step 6: Create the External EPG.
  • Step 7: Associate the L3Out with the BD.
  • Step 8: Set The BD Subnet to Advertise Externally.
  • Step 9: Use Contracts between the External and Application EPGs.

Looking for Comprehensive Cisco Data Center Training?

Take your data center skills to the next level with my deep-dive courses, designed for real-world application.

Modern DC Architecture & Automation:


Core Protocols & CCIE Prep:


Need Personalized Guidance?

Additional Resources: ACI Fabric L3Out White Paper

author avatar
Salman Alhiary Expert Network Consultant
In the networking field since 2010, 2× CCIE (ENT & DC), and founder of LearnWithSalman—specializes in Cisco Data Center networking and automation. A former Cisco TAC engineer and now an Expert Professional Services consultant, he delivers lab-first tutorials, deep templates, and repeatable playbooks through his courses and technical blog, all built from real enterprise projects.
0 0 votes
Article Rating
Subscribe
Notify of
guest

0 Comments
Newest
Oldest Most Voted
Inline Feedbacks
View all comments
Scroll to Top