Part-49: 🌐 Google Cloud VPC – Auto Mode vs Custom Mode (with VM Deployment)

#googlecloud #vpc #cloud #tutorial

In this guide, we’ll explore how to create and use Auto-mode and Custom-mode VPC networks in Google Cloud. We’ll also launch a VM instance in a custom subnet and verify.

✅ Step-01: Introduction

We will perform the following steps:

Create Auto Mode VPC Network
Create Custom VPC Network
Create Subnet in Custom VPC Network
Launch a VM instance inside the custom subnet with a webserver startup script
Verify deployment
Clean-Up resources

✅ Step-02: Understand Default VPC Network

Navigate to VPC Network → default.
Notice that default subnets are pre-created and ready to use in all regions.

✅ Step-03: Auto Mode VPC Network

Step-03-01: Create Auto Mode VPC

Go to VPC Network → CREATE VPC NETWORK
Name: vpc1-auto
Description: Automode VPC
Subnets: Automatic
Firewall Rules:

allow-custom (internal access)
allow-icmp
allow-rdp
allow-ssh

Dynamic Routing Mode: Regional (default)
Click CREATE

Step-03-02: Verify Auto Mode VPC

Go to vpc1-auto → Subnets
Verify that subnets are automatically created in each region.

✅ Step-04: Custom Mode VPC Network

Step-04-01: Create Custom Mode VPC

Go to VPC Network → CREATE VPC NETWORK
Name: vpc2-custom
Description: Custom-mode-VPC
Subnets: Custom
Firewall Rules:

allow-ssh
allow-icmp

Dynamic Routing Mode: Regional (default)
Click CREATE

Step-04-02: Create a Subnet

Go to VPC Networks → vpc2-custom → Subnets → ADD SUBNET

Name: mysubnet1
Region: us-central1
IP Stack: IPv4
Subnet Range: 10.225.0.0/20
Leave others default → Click ADD

✅ Step-05: Create VM Instance in Custom Subnet

Using gcloud CLI:

# Set Project 
gcloud config set project PROJECT_ID
gcloud config set project gcp-zero-to-hero-468909

# Create VM in mysubnet1
gcloud compute instances create myvm1 \
    --zone=us-central1-a \
    --machine-type=e2-micro \
    --network-interface=subnet=mysubnet1 

# List Compute Instances (Optional)
gcloud compute instances list   

# Describe Network Details (Optional)
gcloud compute instances describe myvm1 --zone=us-central1-a

# Connect to VM (Optional)
gcloud compute ssh --zone "us-central1-a" "myvm1" --project "gcp-zero-to-hero-468909"

✅ Step-06: Verify Deployment

Confirm that VM is deployed inside vpc2-custom → mysubnet1.
Check the internal IP address.
If you added a startup script with webserver installation (Apache/Nginx), open the external IP in browser to verify.

✅ Step-07: Clean-Up

# List Instances
gcloud compute instances list 

# Delete VM
gcloud compute instances delete myvm1 \
    --zone=us-central1-a \
    --delete-disks=all