🚀 Module 1: Introduction to NetDevOps

🤔 Part 1: Why NetDevOps? (30 Min)

Pain Points in Everyday Network Operations

Before we look at what NetDevOps is, let us ask ourselves: What is currently going wrong? Here are typical situations that probably every network engineer knows:

What is NetDevOps exactly?

NetDevOps = Network + DevOps. It brings proven practices from software development into the networking world:

• Version Control: Every change is saved, like "Track Changes" in Word – only better.
• Automation: Machines do the boring, repetitive work.
• Testing: Changes are verified before they are deployed to production.
• Continuous Integration: Small, frequent changes instead of big-bang rollouts.

Analogy: The Restaurant

Imagine you are running a restaurant:

Analogy: The Car Factory

Or think of a car factory:

The Traditional Way vs. NetDevOps

📝 Part 2: Infrastructure as Code (IaC) (15 Min)

The core of NetDevOps is Infrastructure as Code (IaC). The idea is simple: Instead of entering configurations manually via a CLI or GUI, you describe the desired state in text files.

What does "as Code" mean?

When we say "as Code", we mean:

• Text files: Readable, editable, searchable
• Versioned: Stored in Git, every change traceable
• Declarative: You describe WHAT you want, not HOW
• Executable: A tool reads the file and implements it

Imperative vs. Declarative

This is an important distinction:

Benefits of IaC

A Concrete Example

This is what Infrastructure as Code looks like for a VXLAN fabric:

📋 Copy# Infrastructure as Code - VXLAN Fabric Definition
# This file describes the TARGET STATE of our fabric

fabric:
  name: FI-DataCenter-Prod
  fabric_type: vxlan_evpn

  # BGP configuration
  bgp:
    asn: 65001

  # Underlay network
  underlay:
    protocol: ospf
    area: 0.0.0.0
    network: 10.0.0.0/8

  # Spine switches
  spines:
    - name: dc1-spine-1
      management_ip: 10.1.1.1
      loopback: 10.255.1.1
      role: spine

    - name: dc1-spine-2
      management_ip: 10.1.1.2
      loopback: 10.255.1.2
      role: spine

  # Leaf switches
  leaves:
    - name: dc1-leaf-1
      management_ip: 10.1.2.1
      loopback: 10.255.2.1
      role: leaf
      uplinks:
        - spine: dc1-spine-1
          interface: Eth1/49
        - spine: dc1-spine-2
          interface: Eth1/50

    - name: dc1-leaf-2
      management_ip: 10.1.2.2
      loopback: 10.255.2.2
      role: leaf
      uplinks:
        - spine: dc1-spine-1
          interface: Eth1/49
        - spine: dc1-spine-2
          interface: Eth1/50

  # VRFs and networks are defined in separate files
  # See: networks/ folder

This file is readable, versionable, and states exactly how the fabric should look. No ambiguity, no "only Klaus knows that" moments.

🌐 Part 3: VXLAN/EVPN Basics (15 Min)

Before we do VXLAN as Code, we should understand WHAT VXLAN and EVPN actually are. Don't worry, we will keep it understandable – no RFC recitation!

The Problem: VLANs Don't Scale

Classic VLANs have a problem: They only exist at Layer 2 and are limited to 4096 (12-bit VLAN ID). In modern data centers with virtualization, multi-tenancy, and cloud requirements, that is no longer enough.

The Solution: VXLAN

VXLAN (Virtual Extensible LAN) solves these problems by encapsulating Layer 2 frames in UDP packets and tunneling them over a Layer 3 network.

Analogy: The Postal Service

Imagine you want to send a letter from Munich to Hamburg, but you can only communicate within your office building (Layer 2):

What is EVPN?

EVPN (Ethernet VPN) is the "Control Plane" for VXLAN. It determines WHO can talk to WHOM and WHERE the MAC addresses are.

EVPN Benefits

• No Flooding: Instead of flooding broadcasts, switches exchange information via BGP
• Fast Convergence: BGP is fast and stable
• Multi-Homing: A server can be connected to multiple switches (active/active)
• Layer 2 + Layer 3: EVPN can do both – distribute MAC addresses AND IP routes

VXLAN Fabric Topology

                    ┌─────────────┐     ┌─────────────┐
                    │   SPINE-1   │     │   SPINE-2   │
                    │  (BGP RR)   │     │  (BGP RR)   │
                    └──────┬──────┘     └──────┬──────┘
                           │                   │
           ┌───────────────┼───────────────────┼───────────────┐
           │               │                   │               │
     ┌─────┴─────┐   ┌─────┴─────┐       ┌─────┴─────┐   ┌─────┴─────┐
     │  LEAF-1   │   │  LEAF-2   │       │  LEAF-3   │   │  LEAF-4   │
     │  (VTEP)   │   │  (VTEP)   │       │  (VTEP)   │   │  (VTEP)   │
     └─────┬─────┘   └─────┬─────┘       └─────┬─────┘   └─────┬─────┘
           │               │                   │               │
        Server          Server              Server          Server
        

📊 Part 4: Nexus Dashboard & NDFC (10 Min)

Now we know WHAT VXLAN/EVPN is. But how do you configure that on 50 switches? This is where Nexus Dashboard comes in.

What is Nexus Dashboard?

Nexus Dashboard is Cisco's central management platform for datacenter networks. It is like the cockpit for your entire fabric.

What is NDFC?

🔍 Enlarge

NDFC (Nexus Dashboard Fabric Controller) – formerly DCNM (Data Center Network Manager) – is THE component for us. NDFC:

• Knows all switches and their connections
• Generates the complete VXLAN/EVPN configuration
• Pushes configs to the switches
• Shows the current status of the fabric
• Provides a REST API for automation (👈 That is what we use!)

The Workflow with NDFC

🔬 Part 5: Hands-on Exercises (15 Min)

Enough theory! Time to get your hands dirty. In the following exercises, you will explore your lab environment.

🧪 Exercise 1: Explore the Lab Environment (5 Min)

Your lab environment runs in the Cisco Cloud. Follow these steps to access your personal environment:

🔐 Access to the Lab Environment

1. Log in at dcloud.cisco.com
2. Click on "My Hub"
3. Select "Sessions"
4. Click "View" on your assigned session
5. Open the WebRDP connection to connect via Remote Desktop to the Windows machine running in the browser

🔍 Enlarge

On the Windows machine, you have access to all lab components. Open the following services in separate browser tabs:

1. VS Code

VS Code is installed locally on the desktop. Launch it via the desktop icon.

→ This is where we write and edit our code

2. GitLab

📋 CopyURL: https://198.18.133.100/
Username: root
Password: C1sco12345

→ This is where we version our code and trigger pipelines

3. Nexus Dashboard (NDFC)

📋 CopyURL: https://198.18.133.101/
Username: admin
Password: C1sco12345

→ This is where we see our fabric and what has been deployed

4. Cisco Modeling Labs (CML)

📋 CopyURL: https://198.18.134.1/
Username: admin
Password: C1sco12345
Lab Name: FI - VXLAN as Code Workshop

→ This is where our simulated VXLAN/EVPN fabric with Nexus switches runs

⚠️ Important: The lab "FI - VXLAN as Code Workshop" must be started first! Click on the lab and then on "Start Lab". Booting up takes a few minutes — wait until all nodes are green.

🔌 Switches in the Lab

Switch	IP	Username	Password
spine01	198.18.1.181	ndfc	C1sco12345
leaf01	198.18.1.182	ndfc	C1sco12345
spine02	198.18.1.183	ndfc	C1sco12345
leaf02	198.18.1.184	ndfc	C1sco12345

💡 You can use mRemoteNG to access the switches via CLI, or use the Terminal directly in CML.

✅ Checklist:

• ☐ VS Code is open and showing the project
• ☐ GitLab shows the repository
• ☐ NDFC login works
• ☐ CML is reachable and the lab is running
• ☐ Switch access tested via mRemoteNG or CML Terminal

❓ Part 6: Quiz & Reflection (5 Min)

Test your knowledge! Try to answer the questions without scrolling back.

📋 Summary