Google Cloud Network Connectivity Center Tutorial: Architecture, Pricing, Use Cases, and Hands-On Guide for Networking

1. Introduction

What this service is

Network Connectivity Center is Google Cloud’s hub-and-spoke connectivity management service for building and operating hybrid and multi-network connectivity in a centralized, scalable way.

One-paragraph simple explanation

If you have multiple networks—like on-prem sites connected with VPN or Interconnect, plus multiple VPC networks in Google Cloud—Network Connectivity Center lets you connect them using a hub and spokes, so you can avoid complex point-to-point designs and manage routing and connectivity in one place.

One-paragraph technical explanation

Technically, Network Connectivity Center provides a control plane to attach multiple network “spokes” (for example, Cloud VPN, Cloud Interconnect VLAN attachments, router appliances, and (where supported) VPC network spokes) to a hub. It orchestrates route exchange between these spokes, enabling transitive routing across networks in a controlled hub-and-spoke model. Data traffic continues to flow over the underlying Google Cloud networking primitives (VPN, Interconnect, Cloud Router/BGP, VPC routing), while Network Connectivity Center coordinates connectivity and routing policy at scale.

What problem it solves

Without Network Connectivity Center, organizations often build brittle “meshes” of VPNs, VPC peering, or custom routing appliances. This leads to:

Too many point-to-point links to manage
Inconsistent route propagation and routing policy
Higher operational risk during changes
Hard-to-audit connectivity between environments
Scaling limits (route tables, BGP sessions, peering sprawl)

Network Connectivity Center is designed to reduce that complexity by providing a central connectivity construct (hub) and standardized attachments (spokes) with controlled route exchange.

Service status and naming: Network Connectivity Center is an active Google Cloud Networking service. If you encounter older references to “transit hub” patterns or third‑party “transit VPC” designs, those are architectural concepts; the product name remains Network Connectivity Center. Always verify the latest supported spoke types and features in the official documentation.

2. What is Network Connectivity Center?

Official purpose

Network Connectivity Center’s purpose is to provide centralized, policy-driven connectivity between multiple networks across Google Cloud and on‑premises environments using a hub-and-spoke model.

Official documentation (start here):
https://cloud.google.com/network-connectivity-center/docs/overview

Core capabilities

At a high level, Network Connectivity Center helps you:

Create a hub as a central connectivity domain.
Attach different types of spokes (connectivity endpoints).
Enable and control route exchange between spokes.
Scale hybrid connectivity while keeping routing manageable.
Reduce the need for full mesh VPNs/peerings.

Major components

While exact feature names evolve, Network Connectivity Center generally revolves around:

Hub
The central connectivity construct.
Where routing exchange and connectivity policy are applied.
Spokes
Attachments that represent connectivity endpoints.
Common spoke types include:
- VPN spokes (Cloud VPN / HA VPN tunnels)
- Interconnect spokes (VLAN attachments for Dedicated/Partner Interconnect)
- Router appliance spokes (third-party or self-managed routing appliances, often BGP-based)
- VPC spokes (where supported; used to connect VPC networks through the hub model—verify current availability and constraints in official docs)
Route exchange / route propagation controls
Controls which routes are shared across which spokes (for example using route tables/associations if supported in your release—verify in official docs).

Service type

Network Connectivity Center is primarily a managed networking control-plane service that coordinates connectivity and routing across underlying data-plane constructs such as:

Cloud Router (BGP)
HA VPN
Cloud Interconnect
VPC routing

Traffic does not “terminate” at Network Connectivity Center like a traditional firewall; instead, NCC orchestrates how routes are exchanged so that traffic can flow between networks through supported connectivity.

Scope: regional/global and resource boundaries

Network Connectivity Center is designed to manage connectivity across regions and across multiple networks.
Many underlying attachments (VPN tunnels, VLAN attachments, Cloud Routers) are regional resources.
Hubs/spokes are managed at the project level and may be treated as global constructs with regional attachments depending on spoke type.

Because the exact scoping and availability can change (and differs by spoke type), verify hub/spoke scope and constraints in the official docs for your intended design: https://cloud.google.com/network-connectivity-center/docs/concepts/overview (navigate from overview)

How it fits into the Google Cloud ecosystem

Network Connectivity Center sits in the Google Cloud Networking portfolio alongside:

VPC networks (your private IP networks)
Cloud Router (dynamic routing/BGP)
Cloud VPN / HA VPN (encrypted tunnels)
Cloud Interconnect (private, high-throughput connectivity)
Network Intelligence Center (connectivity tests, topology, performance insights)
Cloud DNS, Cloud NAT, firewall rules, and routing policies (traffic control)

Network Connectivity Center’s value is not replacing these services, but organizing them into a scalable connectivity architecture.

3. Why use Network Connectivity Center?

Business reasons

Faster network expansion: Add new sites or environments as spokes without redesigning a mesh.
Standardized connectivity: A repeatable hub-and-spoke pattern reduces ad hoc networking.
Reduced outage risk: Central policies and consistent routing reduce change-related incidents.
Supports mergers and multi-environment growth: Easier to connect newly acquired networks or new business units.

Technical reasons

Hub-and-spoke routing at scale: Avoid N×(N−1)/2 connectivity growth inherent in full mesh designs.
Transitive connectivity (where supported): Connect on‑prem ↔ cloud ↔ other sites without building point-to-point links everywhere.
Route exchange orchestration: Central place to manage which routes are shared and with whom (feature specifics depend on your NCC capabilities—verify in official docs).
Leverages Google Cloud’s routing stack: Integrates with Cloud Router/BGP, VPN, and Interconnect.

Operational reasons

Central inventory: A hub provides a clear view of what’s connected.
Change management: Add/remove spokes predictably.
Easier troubleshooting: Standardized constructs simplify connectivity tests and incident response (often paired with Network Intelligence Center).

Security/compliance reasons

Segmentation by design: Use separate hubs or route exchange controls to limit which networks can talk.
Auditability: Control-plane actions are typically visible in Cloud Audit Logs (verify logs available for NCC resources in your environment).
Reduced “shadow connectivity”: Fewer ad hoc VPNs/peerings.

Scalability/performance reasons

Scales better than peering meshes: Especially when connecting many VPCs and many sites.
Works with high-throughput connectivity: Interconnect spokes can provide private high bandwidth links, while NCC organizes routing.

When teams should choose it

Choose Network Connectivity Center when you have:

Multiple on-prem locations connecting to Google Cloud via VPN/Interconnect
Multiple VPC networks that need controlled connectivity
A need for transitive routing and centralized connectivity governance
A desire to reduce complexity of “hub routers” you manage yourself

When they should not choose it

Network Connectivity Center may not be the best fit if:

You only have one VPC and one on-prem site (a simple HA VPN or Interconnect + Cloud Router may be sufficient).
You require advanced traffic inspection (you’ll need separate security appliances or cloud firewalls; NCC is not a firewall).
Your design depends on unsupported route policies or spoke types (verify NCC feature support first).
You need direct service-to-service private publishing (consider Private Service Connect for producer/consumer service connectivity).

4. Where is Network Connectivity Center used?

Industries

Network Connectivity Center is common in industries with many sites and strict network controls:

Financial services (branch connectivity, segmentation, audit requirements)
Retail (store networks to central apps)
Healthcare (multi-site clinics, compliance-driven segmentation)
Manufacturing (plants, OT/IT separation, central analytics)
Media/entertainment (distributed production sites)
Government/public sector (multi-agency connectivity domains)

Team types

Cloud platform teams building landing zones
Network engineering teams modernizing WAN connectivity
DevOps/SRE teams operating multi-environment connectivity
Security teams designing segmentation and connectivity governance
Enterprise architects standardizing hybrid patterns

Workloads

Shared services (identity, logging, monitoring, CI/CD)
Centralized data platforms (data lakes, analytics)
SAP and enterprise apps
Kubernetes clusters spanning multiple environments
Internal APIs consumed across networks

Architectures

Hybrid hub-and-spoke (on-prem ↔ cloud)
Multi-VPC hub-and-spoke (many VPCs, fewer peerings)
Multi-region connectivity using regional attachments (VPN/Interconnect) organized centrally
Segmented hubs (prod hub, non-prod hub, partner hub)

Real-world deployment contexts

Migrating a legacy MPLS + on-prem DMZ into Google Cloud with controlled connectivity
Consolidating multiple VPN topologies into standardized NCC hubs
Connecting many branch sites to cloud-based shared services

Production vs dev/test usage

Production: NCC is typically used to enforce repeatable connectivity patterns with strong change control.
Dev/test: Common when teams are prototyping hybrid connectivity or validating routing/segmentation policies before production rollout.

5. Top Use Cases and Scenarios

Below are realistic scenarios where Network Connectivity Center is typically a strong fit.

1) Central hub for many on-prem sites using HA VPN

Problem: Dozens of branches need secure access to cloud workloads; mesh VPN is unmanageable.
Why NCC fits: Each site becomes a spoke; hub centralizes route exchange.
Example: 60 retail stores connect to a shared services VPC hosting inventory APIs.

2) Central hub for Dedicated/Partner Interconnect VLAN attachments

Problem: Multiple Interconnect VLAN attachments across regions need consistent routing and governance.
Why NCC fits: Attach VLAN attachments as spokes; manage route exchange centrally.
Example: Two Interconnect locations provide redundant connectivity for a data center to multiple cloud environments.

3) Connect third-party router appliances to Google Cloud for advanced routing

Problem: You need specialized routing/segmentation features not handled solely by basic cloud routing.
Why NCC fits: Router appliance spokes can integrate routing appliances into the hub model.
Example: A virtual router appliance terminates BGP and advertises segmented routes into NCC.

4) Multi-VPC connectivity without peering sprawl (where VPC spokes are supported)

Problem: 20 VPCs need shared services; peering becomes complex and error-prone.
Why NCC fits: Hub-and-spoke connectivity replaces many peerings.
Example: Shared logging and CI/CD VPC connects to many application VPCs.

5) Controlled transitive routing (site A ↔ site B via cloud)

Problem: Two sites must communicate, but you don’t want to build site-to-site VPN directly.
Why NCC fits: NCC can enable transitive route exchange across spokes (subject to supported configuration).
Example: A DR site needs access to primary site services through cloud connectivity.

6) Segmented connectivity domains (prod vs non-prod)

Problem: Production and non-production must never exchange routes.
Why NCC fits: Use separate hubs (or route control features if available) to enforce segmentation.
Example: Shared tooling exists in non-prod, but prod uses a separate hub and separate connectivity.

7) Gradual migration from legacy WAN to cloud-based connectivity

Problem: You must migrate in phases while keeping sites connected.
Why NCC fits: Add spokes incrementally; central hub simplifies phased routing changes.
Example: Over 12 months, each region migrates to Interconnect spokes while older VPN spokes remain.

8) Centralized governance for network changes

Problem: Multiple teams create VPNs/peerings independently causing outages.
Why NCC fits: Platform team controls hub/spoke attachment via IAM and change process.
Example: Only the network platform group can attach spokes to the production hub.

9) Standard pattern for M&A network integration

Problem: Newly acquired company networks must connect quickly but safely.
Why NCC fits: Attach new connectivity as isolated spokes; gradually open routes.
Example: Acquire a subsidiary; initially only allow connectivity to identity and email services.

10) Multi-region hybrid architecture with consistent routing

Problem: Different regions have different connectivity methods; routing becomes inconsistent.
Why NCC fits: Common hub constructs and standardized spoke attachments reduce drift.
Example: US uses Dedicated Interconnect; EU uses Partner Interconnect; APAC uses HA VPN—managed centrally.

11) Central hub for shared services + data platform access

Problem: Many application networks need access to a central data platform with least privilege routing.
Why NCC fits: Use hub route exchange controls (where supported) and segmentation boundaries.
Example: Only selected application spokes import routes to BigQuery connector services and internal APIs.

12) Operational visibility and troubleshooting standardization

Problem: Troubleshooting many tunnels/attachments is slow and inconsistent.
Why NCC fits: NCC provides a consistent model to attach networks; pair with Network Intelligence Center for tests/topology.
Example: Standard runbooks for diagnosing route advertisement vs firewall vs tunnel issues.

6. Core Features

Note: Feature availability can differ by spoke type and release track. Always confirm supported spoke types, limits, and routing behaviors in the official documentation.

Hub-and-spoke connectivity model

What it does: Lets you create hubs and attach spokes to build a structured connectivity topology.
Why it matters: Replaces unmanageable full-mesh connectivity.
Practical benefit: Adding a new site often means adding one spoke, not configuring peerings to every other network.
Limitations/caveats: Hub/spoke scoping and supported attachments vary—verify in official docs.

Spoke types for hybrid connectivity

What it does: Supports attaching different connectivity endpoints (commonly VPN, Interconnect VLAN attachments, router appliances; sometimes VPC spokes depending on feature set).
Why it matters: A single operating model across different transport types.
Practical benefit: Consistent governance and change process for new connectivity.
Limitations/caveats: Each spoke type has prerequisites (Cloud Router/BGP, specific regions, redundancy expectations).

Centralized route exchange (transitive routing)

What it does: Exchanges routes between spokes through the hub so networks can communicate transitively.
Why it matters: Enables on-prem ↔ VPC ↔ on-prem patterns without extra point-to-point links.
Practical benefit: Fewer tunnels and simpler routing domains.
Limitations/caveats: Overlapping IP ranges and route conflicts can prevent intended propagation. Some routing control features may require specific hub configurations—verify in official docs.

Routing policy controls (route tables / selective exchange)

What it does: In supported configurations, lets you control which spokes can exchange which routes (for segmentation).
Why it matters: Not all networks should see all routes.
Practical benefit: Implement “shared services” patterns safely.
Limitations/caveats: Exact mechanisms (route tables, associations, filters) depend on your NCC capabilities—verify in official docs and test in non-prod.

Integration with Cloud Router and BGP

What it does: Uses Cloud Router for dynamic routing for VPN/Interconnect/router appliances.
Why it matters: Dynamic routing is the foundation for scalable hybrid connectivity.
Practical benefit: Faster failover and simpler route management than static routes.
Limitations/caveats: BGP session limits, route advertisement limits, and timer behaviors still apply.

Centralized connectivity operations (control plane)

What it does: Provides an API/console surface to manage attachments and connectivity domains.
Why it matters: Enables Infrastructure-as-Code and standardized operations.
Practical benefit: You can treat connectivity as code using Terraform or gcloud (where supported).
Limitations/caveats: Underlying services (VPN, Interconnect) still have their own operational lifecycle and monitoring.

Works with Google Cloud’s global network (via underlying transports)

What it does: Organizes connectivity that ultimately traverses Google’s network using VPN/Interconnect.
Why it matters: Global reach and consistent performance model.
Practical benefit: Hybrid traffic can take advantage of Google’s backbone (especially with Interconnect).
Limitations/caveats: Data path characteristics depend on the underlying transport and region pair; egress charges still apply.

IAM-based governance

What it does: Uses Google Cloud IAM to control who can create hubs/spokes and attach resources.
Why it matters: Connectivity changes are high risk.
Practical benefit: Enforce least privilege and approval workflows.
Limitations/caveats: You often need permissions on both NCC resources and the underlying networking resources.

7. Architecture and How It Works

High-level architecture

Network Connectivity Center provides a central “hub” where multiple “spokes” attach. Spokes represent connectivity endpoints like VPN tunnels, Interconnect VLAN attachments, router appliances, and (in supported cases) VPC networks. Routes learned from one spoke can be propagated to other spokes based on hub configuration.

Control flow vs data flow

Control plane (NCC):
You define hubs/spokes and how routes should be exchanged.
NCC coordinates routing exchange policies.
Data plane (underlying services):
Actual packets flow over VPN tunnels, Interconnect, and VPC routing.
Cloud Router participates in BGP for dynamic route exchange for VPN/Interconnect/router appliances.

Integrations with related services

Common integrations include:

Cloud VPN / HA VPN: Encrypted connectivity from sites to Google Cloud.
Cloud Interconnect (Dedicated/Partner): Private high-throughput connectivity.
Cloud Router: BGP for dynamic routing to VPN/Interconnect/router appliances.
VPC networks: Where your workloads run; may be attached as spokes depending on current NCC support.
Network Intelligence Center: Connectivity tests and topology mapping for troubleshooting.
Cloud Logging / Cloud Audit Logs: Governance and auditing of configuration changes.

Dependency services

Your NCC design typically depends on:

VPC networks and subnets
Cloud Router (for BGP-based spokes)
HA VPN gateways and tunnels (for VPN spokes)
Interconnect attachments (for Interconnect spokes)
Firewall rules, routes, and possibly Cloud NAT (for workload access patterns)

Security/authentication model

Administration access is governed by Google Cloud IAM.
Data plane security (encryption, integrity, segmentation) depends on:
VPN encryption for Cloud VPN
Private nature of Interconnect (note: Interconnect traffic is not encrypted by default; you can encrypt at higher layers if required)
VPC firewall rules and network policies
Any router appliances you deploy

Networking model considerations

Routing is fundamental. A correct NCC deployment is mostly about:
Non-overlapping CIDR planning
Route advertisement boundaries
Avoiding asymmetric routing
Ensuring firewall rules allow intended traffic
NCC doesn’t replace firewalls. Use:
VPC firewall rules
Network Firewall policies (where applicable)
Third-party or Cloud NGFW solutions for inspection

Monitoring/logging/governance considerations

Monitor the underlying connectivity:
VPN tunnel status, BGP session state (Cloud Router)
Interconnect attachment status and capacity
VPC Flow Logs for actual traffic verification
Audit NCC configuration changes using Cloud Audit Logs.
Use Network Intelligence Center for connectivity tests and topology (recommended for ops).

Simple architecture diagram (conceptual)

flowchart LR
  OnPrem[On‑prem / Branch Sites] -->|HA VPN / Interconnect| Spoke1[Spoke: VPN/Interconnect]
  VPC1[VPC Network A] --> Spoke2[Spoke: VPC (if supported)]
  VPC2[VPC Network B] --> Spoke3[Spoke: VPC (if supported)]

  Spoke1 --> Hub[Network Connectivity Center Hub]
  Spoke2 --> Hub
  Spoke3 --> Hub

  Hub -->|Route exchange| Spoke1
  Hub -->|Route exchange| Spoke2
  Hub -->|Route exchange| Spoke3

Production-style architecture diagram (hybrid + segmentation)

flowchart TB
  subgraph Sites[On‑prem Sites]
    DC1[Primary DC]
    DC2[DR DC]
    Branches[Branches]
  end

  subgraph GCP[Google Cloud]
    subgraph Prod[Prod Environment]
      HubProd[NCC Hub: prod-hub]
      VPCProd1[Prod VPC: payments]
      VPCProd2[Prod VPC: core-services]
      InterconnectSpoke[Spoke: Interconnect VLAN attachments]
      VPNSpoke[Spoke: HA VPN (backup)]
    end

    subgraph NonProd[Non-Prod Environment]
      HubNonProd[NCC Hub: nonprod-hub]
      VPCDev[Dev VPC]
      VPCTest[Test VPC]
    end

    Sec[Security Controls:\nFirewall rules / policies\n(plus optional NGFW)]
    Obs[Operations:\nCloud Logging\nCloud Monitoring\nNetwork Intelligence Center]
  end

  DC1 -->|Dedicated/Partner Interconnect| InterconnectSpoke --> HubProd
  DC1 -->|HA VPN backup| VPNSpoke --> HubProd
  DC2 -->|HA VPN| VPNSpoke
  Branches -->|HA VPN| VPNSpoke

  VPCProd1 --> HubProd
  VPCProd2 --> HubProd

  VPCDev --> HubNonProd
  VPCTest --> HubNonProd

  HubProd --> Sec
  HubNonProd --> Sec
  HubProd --> Obs
  HubNonProd --> Obs

8. Prerequisites

Account/project requirements

A Google Cloud project with Billing enabled.
An Organization is strongly recommended for enterprise governance (not strictly required for basic labs).

Permissions / IAM roles

You typically need: – Permissions to manage Network Connectivity Center: – Example roles (verify exact role names in IAM): – roles/networkconnectivity.admin (admin) – roles/networkconnectivity.viewer (read-only) – Permissions to create and manage underlying network resources: – VPC networks/subnets/firewall rules: roles/compute.networkAdmin (or narrower custom role) – VM creation for test instances: roles/compute.instanceAdmin.v1 – Service account permissions: roles/iam.serviceAccountUser

Principle: give least privilege and separate duties (network platform vs app teams).

Billing requirements

NCC itself may have per-spoke and/or per-data-processing charges (see Pricing section).
Underlying components (VMs, VPN gateways, Cloud Router, Interconnect, egress) generate costs.

CLI/SDK/tools

Optional but recommended:
Google Cloud CLI (gcloud): https://cloud.google.com/sdk/docs/install
For verification tests:
SSH client
Basic networking tools (ping, traceroute)

Region availability

Underlying services are regional (VPN gateways, Cloud Routers, VLAN attachments).
NCC availability and spoke type support can vary by region.
Verify current region support in the official docs before production rollout.

Quotas/limits

You may encounter limits on: – Number of hubs/spokes per project – Number of routes exchanged/propagated – BGP session limits (Cloud Router) – VPN tunnel counts and throughput limits – Interconnect attachment counts and capacity

Always check the current limits here (and in NCC docs): – Quotas page in the console: IAM & Admin → Quotas – NCC documentation for service-specific limits (verify in official docs)

Prerequisite services/APIs

Enable relevant APIs: – Network Connectivity API (NCC) – Compute Engine API (for VPCs/VMs) – Cloud Resource Manager API (often needed for IAM/project operations)

9. Pricing / Cost

Official pricing (start here and verify current SKUs):
https://cloud.google.com/network-connectivity-center/pricing

Pricing calculator (to model full solution cost):
https://cloud.google.com/products/calculator

Pricing changes over time and can differ by region and SKU. Do not rely on blog posts for exact numbers—use the official pricing page and calculator.

Pricing dimensions (typical model)

Network Connectivity Center pricing commonly involves some combination of:

Spoke attachment charges
– A recurring cost per spoke (often hourly).
Data processing / traffic through NCC
– A per‑GB cost for traffic that traverses connectivity enabled by NCC (in some models).
Underlying connectivity costs (separate) – HA VPN charges (tunnel and/or gateway) – Cloud Router charges – Interconnect port and VLAN attachment charges – Standard network egress charges (internet egress, inter-region egress, etc.)

Because SKUs and definitions can evolve, confirm which NCC traffic is billable and how it’s measured in the pricing docs.

Free tier

NCC generally does not advertise a broad “free tier” comparable to some serverless products.
Some customers may have limited free usage for trials/promotions, but assume billable and verify.

Key cost drivers

Number of spokes attached to hubs
Traffic volume between spokes (GB processed, if applicable)
Choice of transport:
VPN (lower fixed costs, potentially lower throughput)
Interconnect (higher fixed cost, high throughput/low latency)
Egress charges:
Inter-region traffic
Traffic to/from on-prem (depending on setup)
VM and appliance costs if you use router appliances

Hidden or indirect costs to plan for

High Availability requirements:
HA VPN typically uses multiple tunnels/gateways; redundancy multiplies components.
Redundant Interconnect requires dual attachments and diverse paths.
Observability costs:
VPC Flow Logs (log volume can be large)
Logging retention
Security controls:
If you insert traffic inspection appliances, you add compute/licensing costs.

Network/data transfer implications

Even if NCC simplifies routing, data transfer pricing still matters:

Traffic between regions can incur inter-region egress.
Traffic leaving Google Cloud to on-prem may have costs depending on service and direction (verify current network pricing).
Interconnect pricing differs for Dedicated vs Partner Interconnect.

Network pricing overview (verify current):
https://cloud.google.com/vpc/network-pricing

How to optimize cost

Minimize unnecessary spoke count (don’t attach networks “just in case”).
Use segmentation to avoid unintended cross-network traffic (which can increase billable processing and egress).
Keep high‑churn dev/test environments on a separate hub and shut down nonessential connectivity.
Prefer regional locality where possible to reduce inter-region egress.
If using router appliances, right-size instances and consider committed use discounts (where applicable).

Example low-cost starter estimate (conceptual)

A “starter lab” cost is typically dominated by: – 2 small VM instances for testing – Minimal logging (Flow Logs off) – Possibly NCC spoke charges (if billed) – Minimal data transfer

Because exact NCC and VM pricing is region-dependent and changes over time, use the calculator and keep the lab duration short (1–2 hours). Do not leave resources running overnight.

Example production cost considerations

For production, plan a cost model that includes: – Number of hubs (prod, non-prod, partner) – Spoke count (sites, VPCs, attachments) – Expected east-west traffic volume across spokes – Underlying transport mix (VPN vs Interconnect) – Logging/monitoring strategy and retention – HA topology (redundant tunnels/attachments/routers) – Growth over 12–36 months

10. Step-by-Step Hands-On Tutorial

This lab demonstrates a practical, beginner-friendly pattern: connect two VPC networks using Network Connectivity Center and validate private IP connectivity between test VMs.

Important: The exact UI labels and spoke options can vary by release and organization policy. If you do not see “VPC spoke” as an option in your environment, use this lab as a conceptual walkthrough and switch to a VPN/Interconnect spoke-based lab instead (verify current supported spoke types in official docs).

Objective

Create: – Two isolated VPC networks (vpc-a, vpc-b) – One Network Connectivity Center hub – Two spokes (one per VPC, if supported) – Verify that a VM in vpc-a can reach a VM in vpc-b using private IP

Lab Overview

You will: 1. Prepare the project and enable APIs 2. Create two VPC networks and subnets 3. Create two test VMs (one in each VPC) 4. Configure firewall rules for ICMP/SSH 5. Create an NCC hub 6. Attach both VPCs as spokes (or the nearest equivalent supported spoke type) 7. Validate connectivity 8. Clean up everything

Step 1: Set up your project, region, and APIs

Select or create a Google Cloud project.
Set a default region (example: us-central1)—choose a region that supports the resources you need.

Enable APIs (Console): – Go to APIs & Services → Library – Enable: – Network Connectivity API – Compute Engine API

Optional CLI setup:

gcloud auth login
gcloud config set project YOUR_PROJECT_ID
gcloud config set compute/region us-central1
gcloud config set compute/zone us-central1-a

Expected outcome: – APIs enabled – gcloud points to the correct project/region/zone

Verification:

gcloud services list --enabled | grep -E "networkconnectivity|compute"

Step 2: Create two VPC networks and subnets

Create two custom-mode VPCs (so you control subnets):

vpc-a with subnet subnet-a CIDR 10.10.0.0/24 in us-central1
vpc-b with subnet subnet-b CIDR 10.20.0.0/24 in us-central1

Console path: – VPC network → VPC networks → Create VPC network – Choose Custom – Add subnet with the CIDR above

Optional CLI:

gcloud compute networks create vpc-a --subnet-mode=custom
gcloud compute networks create vpc-b --subnet-mode=custom

gcloud compute networks subnets create subnet-a \
  --network=vpc-a --range=10.10.0.0/24 --region=us-central1

gcloud compute networks subnets create subnet-b \
  --network=vpc-b --range=10.20.0.0/24 --region=us-central1

Expected outcome: – Two isolated VPCs with non-overlapping IP ranges

Verification:

gcloud compute networks list
gcloud compute networks subnets list --regions=us-central1

Step 3: Create test VMs in each VPC

Create: – vm-a in subnet-a (private IP like 10.10.0.x) – vm-b in subnet-b (private IP like 10.20.0.x)

Console path: – Compute Engine → VM instances → Create instance – Networking: – Choose the correct VPC/subnet – Use small machine types to reduce cost. – You can use a standard public image (Debian/Ubuntu).

Optional CLI:

gcloud compute instances create vm-a \
  --zone=us-central1-a \
  --subnet=subnet-a \
  --machine-type=e2-micro \
  --image-family=debian-12 \
  --image-project=debian-cloud

gcloud compute instances create vm-b \
  --zone=us-central1-a \
  --subnet=subnet-b \
  --machine-type=e2-micro \
  --image-family=debian-12 \
  --image-project=debian-cloud

Expected outcome: – Two VMs running, each reachable by SSH (depending on your access method) – Each VM has a private IP in its own subnet

Verification:

gcloud compute instances list --filter="name:(vm-a vm-b)" \
  --format="table(name,zone,networkInterfaces[0].networkIP)"

Step 4: Add firewall rules to allow testing traffic

You need to allow: – SSH (tcp:22) from your admin IP range (or use IAP-based SSH to avoid opening SSH broadly) – ICMP between the two subnet CIDRs so ping tests work

A simple lab firewall approach (be cautious in production):

gcloud compute firewall-rules create allow-ssh-iap \
  --network=vpc-a \
  --allow=tcp:22 \
  --source-ranges=35.235.240.0/20 \
  --direction=INGRESS \
  --description="Allow SSH from IAP to vm-a"

gcloud compute firewall-rules create allow-ssh-iap \
  --network=vpc-b \
  --allow=tcp:22 \
  --source-ranges=35.235.240.0/20 \
  --direction=INGRESS \
  --description="Allow SSH from IAP to vm-b"

If you will SSH from your own IP instead, replace the source range accordingly.

Allow ICMP between subnets:

gcloud compute firewall-rules create allow-icmp-from-peer \
  --network=vpc-a \
  --allow=icmp \
  --source-ranges=10.20.0.0/24 \
  --direction=INGRESS

gcloud compute firewall-rules create allow-icmp-from-peer \
  --network=vpc-b \
  --allow=icmp \
  --source-ranges=10.10.0.0/24 \
  --direction=INGRESS

Expected outcome: – Firewall permits ICMP between the subnets (once routing exists) – SSH access is possible via IAP (recommended for labs) or your chosen method

Verification: – In the console, check VPC network → Firewall for the rules. – Ensure rules are in the correct VPC (rules are per VPC).

Step 5: Create a Network Connectivity Center hub

Console path: – Network Connectivity Center → Hubs → Create hub

Choose: – Hub name: lab-hub – Description: “Lab hub connecting vpc-a and vpc-b” – Any required routing/association defaults (use defaults for a beginner lab)

Optional CLI (syntax can change; verify with help in your environment):

gcloud network-connectivity hubs create lab-hub --description="Lab hub"
# If flags differ, run:
gcloud network-connectivity hubs create --help

Expected outcome: – A hub exists and is ready to accept spokes

Verification (CLI):

gcloud network-connectivity hubs list
gcloud network-connectivity hubs describe lab-hub

Step 6: Create spokes and attach the VPC networks (if supported)

Console path: – Network Connectivity Center → Spokes → Create spoke – Spoke name: spoke-a – Hub: lab-hub – Spoke type: choose VPC network (if available) – Select VPC: vpc-a – Configure route export/import settings as prompted (use defaults for the lab)

Repeat for: – Spoke name: spoke-b – VPC: vpc-b

If your environment does not offer VPC network spokes: – Stop here and switch to a supported spoke type (VPN or router appliance) and adapt the lab. – Official docs will show current spoke types and setup steps: https://cloud.google.com/network-connectivity-center/docs

Optional CLI (highly dependent on current API; verify flags):

gcloud network-connectivity spokes create spoke-a --hub=lab-hub
gcloud network-connectivity spokes create spoke-b --hub=lab-hub
# Then attach VPCs via the supported flags (verify via --help).
gcloud network-connectivity spokes create --help

Expected outcome: – vpc-a and vpc-b are attached to lab-hub as spokes – Routes for each subnet become available for exchange (subject to config)

Verification: – In NCC console, confirm both spokes show Active/Ready. – Check effective routes in each VPC.

Check routes for vm-a and vm-b (Console): – VPC network → Routes – Filter by network vpc-a and look for a route to 10.20.0.0/24 – Filter by network vpc-b and look for a route to 10.10.0.0/24

CLI route check (works for many route sources, but may not show all dynamic sources uniformly—still useful):

gcloud compute routes list --filter="network:vpc-a AND destRange:10.20.0.0/24"
gcloud compute routes list --filter="network:vpc-b AND destRange:10.10.0.0/24"

Step 7: Test private connectivity between VMs

Find private IPs:

VM_A_IP=$(gcloud compute instances describe vm-a --zone=us-central1-a --format="value(networkInterfaces[0].networkIP)")
VM_B_IP=$(gcloud compute instances describe vm-b --zone=us-central1-a --format="value(networkInterfaces[0].networkIP)")
echo "vm-a: $VM_A_IP"
echo "vm-b: $VM_B_IP"

SSH to vm-a (use IAP if configured, or standard SSH if allowed):

gcloud compute ssh vm-a --zone=us-central1-a --tunnel-through-iap

From vm-a, ping vm-b private IP:

ping -c 5 VM_B_PRIVATE_IP

Expected outcome: – Pings succeed with low latency – This confirms routing + firewall rules allow ICMP

Validation

Use this checklist:

Spokes show ready/active in NCC.
Routes exist:
vpc-a can route to 10.20.0.0/24
vpc-b can route to 10.10.0.0/24
Firewall allows ICMP from the opposite CIDR.
Ping from vm-a to vm-b private IP works.

Optional deeper validation: – Run a TCP test (e.g., nc) if you add firewall rules for a test port. – Enable VPC Flow Logs temporarily to confirm flows (be mindful of log cost).

Troubleshooting

Common issues and fixes:

No route to the other subnet – Confirm both spokes are attached to the same hub. – Confirm route exchange/import/export settings in NCC. – Check if your org policy restricts route export/import. – Verify that VPC spokes are supported in your environment/region.
Ping fails but routes exist – Check firewall rules in both VPCs (ICMP allowed from peer CIDR). – Confirm VM OS firewall (iptables/ufw) isn’t blocking ICMP. – Confirm you’re pinging the correct private IP.
Spoke stuck in provisioning – Ensure the Network Connectivity API is enabled. – Check IAM: you need NCC admin permissions plus rights on the attached resources. – Review Cloud Audit Logs for denied permissions.
SSH access fails – If using IAP, ensure:
- You used --tunnel-through-iap
- Your user has IAP permissions (verify: roles/iap.tunnelResourceAccessor)
- Firewall allows SSH from IAP IP range 35.235.240.0/20
- Alternatively, use serial console access for debugging.

Cleanup

To avoid ongoing costs, delete resources in this order:

Delete NCC spokes
Delete NCC hub
Delete VMs
Delete firewall rules
Delete subnets and VPCs (or delete VPCs directly if they have no dependent resources)

CLI cleanup example:

# NCC (verify commands/flags in your environment)
gcloud network-connectivity spokes delete spoke-a --quiet
gcloud network-connectivity spokes delete spoke-b --quiet
gcloud network-connectivity hubs delete lab-hub --quiet

# VMs
gcloud compute instances delete vm-a vm-b --zone=us-central1-a --quiet

# Firewall rules (adjust names if you used different ones)
gcloud compute firewall-rules delete allow-icmp-from-peer --quiet || true
gcloud compute firewall-rules delete allow-ssh-iap --quiet || true

# Subnets and networks
gcloud compute networks subnets delete subnet-a --region=us-central1 --quiet
gcloud compute networks subnets delete subnet-b --region=us-central1 --quiet
gcloud compute networks delete vpc-a --quiet
gcloud compute networks delete vpc-b --quiet

If deletion fails, it’s usually because a dependent resource still exists (routes, forwarding rules, connectors, etc.). The error message will name the blocker.

11. Best Practices

Architecture best practices

Plan IP addressing early: Avoid overlapping CIDRs across all networks that may connect via NCC. Overlaps are one of the most common causes of route conflicts and blocked propagation.
Design segmentation intentionally:
Separate hubs for prod/non-prod/partner is often simpler than complex conditional policies.
If using route tables/associations, document them like you would firewall rules.
Prefer dynamic routing for hybrid: Use Cloud Router/BGP for VPN and Interconnect spokes to support failover and scale.
Avoid “accidental transit”: Ensure that only intended spokes can exchange routes; don’t attach sensitive networks to broad hubs without segmentation.

IAM/security best practices

Separate duties: Network platform team controls hubs/spokes; app teams control their VPC workloads.
Least privilege: Use viewer roles for most users; restrict create/update/delete on NCC resources tightly.
Use change control: Connectivity changes should follow approvals and maintenance windows where appropriate.
Audit routinely: Review Cloud Audit Logs for NCC and underlying network changes.

Cost best practices

Right-size connectivity: Don’t attach every environment everywhere; attach what you need.
Keep dev/test lean: Separate hubs and shut down ephemeral environments quickly.
Measure traffic patterns: High east-west traffic between spokes can increase overall network costs (including egress/inter-region).

Performance best practices

Use Interconnect for high throughput/low jitter needs.
Keep traffic regional when possible to reduce latency and inter-region costs.
Test failover: For VPN and Interconnect, validate behavior under link failure and route withdrawal.

Reliability best practices

Design redundancy:
HA VPN with recommended redundancy
Dual Interconnect attachments and diverse paths
Avoid single points: Don’t rely on one Cloud Router, one tunnel, or one attachment for critical paths.
Document dependencies: NCC depends on underlying resources—monitor them.

Operations best practices

Standard naming: Include env/region/function in hub and spoke names.
Use labels/tags: Apply consistent labels for cost allocation and inventory.
Create runbooks: Include checks for routes, BGP session state, tunnel status, firewall, and Flow Logs.
Use Network Intelligence Center for connectivity tests and topology in troubleshooting workflows.

Governance/tagging/naming best practices

A practical naming scheme:

Hubs: hub-<env>-<domain> (e.g., hub-prod-shared, hub-nonprod-shared)
Spokes: spoke-<type>-<siteOrVPC>-<region> (e.g., spoke-vpn-branch17-uscentral1)

Label examples: – env=prod|nonprod – owner=net-platform – cost_center=... – connectivity_domain=shared|partner|restricted

12. Security Considerations

Identity and access model

Network Connectivity Center is configured via IAM-controlled APIs.
Use:
Organization policies (if available) to restrict who can create/attach connectivity resources.
Custom roles if built-in roles are too broad.

Recommended approach: – Only a small group can create/modify hubs/spokes. – Separate read-only visibility (viewer) for app teams and security teams.

Encryption

Cloud VPN (HA VPN): Provides encryption in transit for tunnels.
Interconnect: Provides private connectivity, but encryption is not automatic at the link layer; use application-layer encryption or IPsec overlays if required by compliance.
Within Google Cloud, traffic between VMs is protected by Google’s infrastructure security; still, your compliance requirements may demand additional encryption.

Network exposure

NCC itself is not an internet-facing endpoint, but it can enable reachability between networks.
Risks often come from:
Overly broad route propagation
Overly permissive firewall rules
Accidental connectivity between prod and dev
Overlapping CIDRs causing unintended routing

Secrets handling

NCC configuration typically doesn’t store application secrets, but related components might:
VPN shared secrets (if using classic VPN configurations)
Router appliance credentials
Store secrets in Secret Manager and restrict access.

Audit/logging

Enable and review Cloud Audit Logs for:
NCC hub/spoke creation/deletion/updates
IAM policy changes
Underlying VPN/Interconnect/Cloud Router changes
Use VPC Flow Logs selectively to validate traffic paths.

Compliance considerations

Document:
Which networks exchange routes
Why connectivity is needed
What controls (firewalls, inspection) exist
Who can change it and how changes are approved
For regulated environments, ensure encryption requirements are met for on-prem ↔ cloud links.

Common security mistakes

Attaching a sensitive VPC to a broad hub without route restrictions.
Allowing 0.0.0.0/0 routes or broad RFC1918 routes to propagate unintentionally.
Using permissive firewall rules “temporarily” and never reverting them.
Not testing failover—leading to emergency changes that bypass security review.

Secure deployment recommendations

Use separate hubs for strong isolation.
Apply route exchange controls where supported.
Insert inspection where required (firewall appliances, Cloud NGFW) and ensure symmetric routing.
Enforce IAP-based admin access rather than exposing SSH to the internet.

13. Limitations and Gotchas

Always confirm limits and behaviors in the official documentation, as they change over time.

Known limitations (typical)

Spoke type availability varies by region and by feature release.
Overlapping CIDRs across spokes can break intended routing and may be rejected or lead to nondeterministic outcomes.
Route scale constraints exist:
Maximum number of routes exchanged
Maximum number of spokes
Limits inherited from Cloud Router/BGP and VPC routing
Propagation delay: Route updates are not always instantaneous; allow time for convergence during validation.

Quotas

Hubs/spokes per project
Route counts
API request quotas

Check current quotas in: – Google Cloud console quotas – NCC documentation (verify in official docs)

Regional constraints

VPN gateways, Cloud Routers, and VLAN attachments are regional, which affects design and failover planning.

Pricing surprises

NCC charges (spoke and/or data processing) can add up with many spokes or high east-west traffic.
Inter-region egress can be significant if you connect spokes across regions and move a lot of data.

Compatibility issues

Some advanced routing scenarios (multiple overlapping advertisements, complex filtering) may require router appliances or additional design work.
Certain transitive routing patterns might be limited depending on spoke types—verify your desired pattern.

Operational gotchas

“Routes exist” ≠ “traffic flows.” Firewalls, OS ACLs, and asymmetric routing still block traffic.
Change blast radius: Updating a hub policy can affect many spokes; treat changes like core network changes.
Troubleshooting requires multiple layers: NCC attachment status, Cloud Router BGP, VPN tunnel state, VPC routes, firewall, VM OS.

Migration challenges

Migrating from a peering mesh or legacy WAN requires:
IP plan review
staged cutover
route advertisement controls
rollback plan

Vendor-specific nuances

If you use third-party router appliances, routing behavior depends on vendor configuration (BGP attributes, MED/localpref, ECMP).
Validate interoperability with Cloud Router and your appliance’s BGP implementation.

14. Comparison with Alternatives

Network Connectivity Center is one of several ways to build connectivity. The right choice depends on scale, routing needs, governance, and cost.

Alternatives within Google Cloud

VPC Network Peering
Good for simple VPC-to-VPC connectivity.
Not transitive; peering meshes get complex at scale.
Shared VPC
Best for centrally governed networks where multiple projects share a single VPC.
Not a hybrid connectivity solution by itself.
Cloud VPN / HA VPN + Cloud Router (without NCC)
Works well for a small number of sites.
Harder to scale and govern for many sites/VPCs.
Cloud Interconnect + Cloud Router (without NCC)
Excellent performance; still needs a scalable topology and governance model.
Private Service Connect
Best for private service publishing/consumption, not general transitive routing between networks.

Alternatives in other clouds

AWS Transit Gateway
Similar hub-and-spoke concept for VPCs and VPN/Direct Connect.
Azure Virtual WAN
Managed hub for connectivity including VPN/ExpressRoute and branch connectivity.

Open-source/self-managed alternatives

Self-managed transit using NVAs
Deploy routing appliances (FRR, VyOS, vendor routers) and build transit yourself.
More control, more operational burden, more patching and scaling responsibility.

Comparison table

Option	Best For	Strengths	Weaknesses	When to Choose
Network Connectivity Center (Google Cloud)	Hybrid + multi-network hub-and-spoke with centralized governance	Central model, scalable attachments, route exchange, integrates with VPN/Interconnect/Cloud Router	Requires learning NCC model; charges may apply; feature availability depends on spoke types	Many sites/VPCs, need transitive routing and centralized control
VPC Network Peering	Small number of VPC-to-VPC connections	Simple, low latency, no extra gateway appliances	Not transitive; mesh complexity; governance sprawl	2–5 VPCs with simple connectivity needs
Shared VPC	Centralizing networking for many projects	Strong governance, fewer VPCs, simpler security boundaries	Doesn’t connect external networks by itself; org structure requirements	Platform teams standardizing network for many app projects
HA VPN + Cloud Router (no NCC)	A few sites, straightforward hybrid	Mature, encrypted, relatively quick to set up	Operational complexity grows with many sites and multiple VPCs	Small hybrid footprint, limited growth
Interconnect + Cloud Router (no NCC)	High throughput private hybrid	Performance and reliability; private connectivity	Still needs scalable topology; higher fixed costs	Data center ↔ cloud at scale, predictable traffic
AWS Transit Gateway / Azure Virtual WAN	Similar problems in other clouds	Native hub constructs in their ecosystems	Not applicable inside Google Cloud	You are architecting primarily on AWS/Azure
Self-managed NVA transit	Highly customized routing/inspection needs	Maximum control, custom routing policies	High ops burden, patching, HA design complexity	You require features beyond managed constructs and accept operational overhead

15. Real-World Example

Enterprise example: Global retailer with branches and segmented environments

Problem: A retailer has 800 stores and 3 regional data centers. They are migrating POS analytics and inventory services to Google Cloud. They need secure connectivity from stores to cloud services, and strict separation between prod and non-prod.
Proposed architecture:
hub-prod-shared for production connectivity:
- Interconnect spokes to regional data centers
- HA VPN spokes for branch aggregation or backup
- Attach production shared services VPC (where supported) or connect via approved patterns
hub-nonprod-shared for dev/test:
- Separate VPN connectivity and separate VPC attachments
Centralized firewall policy and inspection at controlled choke points (as required)
Network Intelligence Center for topology and connectivity tests
Why Network Connectivity Center was chosen:
Reduces operational overhead of managing hundreds of branch VPNs and multiple cloud environments.
Provides a clear governance boundary with separate hubs.
Enables scalable route exchange without peering meshes.
Expected outcomes:
Faster onboarding of new stores (standard spoke template)
Reduced outage risk from ad hoc routing changes
Easier audits: “what is connected to prod and why”

Startup/small-team example: SaaS company with shared services and future hybrid plans

Problem: A growing SaaS startup has separate VPCs for prod, staging, and shared-tools. Today they use minimal peering, but they expect to add a customer-managed on-prem connector and a partner network soon.
Proposed architecture:
A single NCC hub for non-sensitive connectivity initially (or separate hubs later)
Attach shared-tools and staging VPC as spokes (if supported), keeping prod isolated
When adding customer connectivity, use HA VPN spokes with strict route controls and firewall policies
Why Network Connectivity Center was chosen:
Provides a scalable “future-ready” pattern without rebuilding networking later.
Avoids peering sprawl as environments grow.
Expected outcomes:
Predictable growth path
Clear separation between environments
Less networking rework when hybrid connectivity arrives

16. FAQ

1) Is Network Connectivity Center a data-plane router or a control-plane service?
It is primarily a control-plane service that orchestrates connectivity and route exchange. Actual packet forwarding uses underlying services like VPC routing, Cloud VPN, Interconnect, and Cloud Router.

2) Does Network Connectivity Center replace Cloud Router?
No. For BGP-based connectivity (VPN/Interconnect/router appliances), Cloud Router is still the primary BGP endpoint. NCC coordinates how networks connect and how routes are exchanged at a higher level.

3) Do I still need HA VPN or Interconnect if I use NCC?
Yes. NCC organizes and manages connectivity; VPN/Interconnect provide the actual transport.

4) Can I connect multiple VPC networks with NCC?
Often yes using VPC-related spoke capabilities, but availability and constraints vary. Verify current support and requirements in the official docs.

5) Is VPC Network Peering the same as NCC?
No. Peering is a direct VPC-to-VPC connection and is not transitive. NCC is a hub-and-spoke connectivity model designed to scale and support hybrid patterns.

6) Can NCC help me avoid a full mesh of VPN tunnels?
Yes—this is one of its main benefits. Instead of connecting every site to every other site, you connect sites as spokes to a hub.

7) How do I segment prod and non-prod connectivity?
The simplest approach is separate hubs (prod hub, non-prod hub). If your NCC feature set supports route tables/associations or selective route exchange, you can implement more granular segmentation—verify your options in official docs.

8) Does NCC inspect or filter traffic like a firewall?
No. NCC is not a firewall. Use VPC firewall rules, network firewall policies, or dedicated inspection appliances/services.

9) How do I troubleshoot when routes look correct but traffic fails?
Check, in order: – Spoke attachment status in NCC – Underlying BGP session state (Cloud Router) – VPC routes and priorities – Firewall rules and OS-level firewalls – VPC Flow Logs and connectivity tests (Network Intelligence Center)

10) What’s the biggest design mistake with NCC?
Poor IP planning (overlapping ranges) and attaching too many networks to a hub without segmentation, resulting in unintended reachability.

11) Does NCC support high availability?
High availability comes from the underlying connectivity design (redundant tunnels, routers, attachments). NCC supports managing multiple redundant spokes/attachments, but you must architect HA properly.

12) Will NCC reduce latency?
NCC itself doesn’t “accelerate” traffic; performance depends on VPN vs Interconnect, region placement, and routing. NCC can improve operational efficiency and consistency, which indirectly helps performance management.

13) Is traffic through NCC billable?
NCC pricing may include per-spoke and/or per-GB processing. Always check the official pricing page for current SKUs and definitions.

14) Can I use Infrastructure-as-Code with NCC?
Yes. Many teams use Terraform and/or gcloud for NCC and related networking resources. Verify provider/resource support and API versions in your tooling.

15) How does NCC relate to Network Intelligence Center?
NCC is for building and managing connectivity. Network Intelligence Center is for observability and testing (topology, connectivity tests, performance). They are complementary.

16) Can NCC connect to third-party appliances?
Yes, via router appliance spokes in supported configurations. The exact requirements depend on your appliance and NCC support—verify in official docs.

17) What should I monitor most?
Monitor underlying transports: VPN tunnel health, BGP session state, Interconnect attachment health, throughput, packet loss, and VPC Flow Logs for traffic verification.

17. Top Online Resources to Learn Network Connectivity Center

Resource Type	Name	Why It Is Useful
Official documentation	Network Connectivity Center documentation	Primary source for concepts, spoke types, configuration, limits, and best practices. https://cloud.google.com/network-connectivity-center/docs
Official overview	Network Connectivity Center overview	Quick orientation to hubs/spokes and supported patterns. https://cloud.google.com/network-connectivity-center/docs/overview
Official pricing	Network Connectivity Center pricing	Current SKUs and pricing dimensions. https://cloud.google.com/network-connectivity-center/pricing
Pricing tool	Google Cloud Pricing Calculator	Model end-to-end solution costs (NCC + VPN/Interconnect + egress). https://cloud.google.com/products/calculator
Related networking docs	Cloud VPN documentation	Required for VPN-based spokes and hybrid encryption. https://cloud.google.com/network-connectivity/docs/vpn
Related networking docs	Cloud Interconnect documentation	Required for Interconnect-based spokes. https://cloud.google.com/network-connectivity/docs/interconnect
Related routing docs	Cloud Router documentation	BGP fundamentals for hybrid routing. https://cloud.google.com/network-connectivity/docs/router
Troubleshooting/visibility	Network Intelligence Center	Connectivity tests and topology help validate NCC designs. https://cloud.google.com/network-intelligence-center/docs
CLI reference	gcloud network-connectivity reference	Command reference for NCC resources (verify commands per version). https://cloud.google.com/sdk/gcloud/reference/network-connectivity
Training platform (official)	Google Cloud Skills Boost catalog search	Find current labs/quests related to NCC and hybrid networking. https://www.cloudskillsboost.google/catalog?keywords=Network%20Connectivity%20Center
Videos (official)	Google Cloud Tech (YouTube)	Official talks and demos across Google Cloud networking topics. https://www.youtube.com/@googlecloudtech
Architecture center	Google Cloud Architecture Center	Reference architectures for hybrid networking (browse/search for NCC patterns). https://cloud.google.com/architecture

18. Training and Certification Providers

Institute	Suitable Audience	Likely Learning Focus	Mode	Website URL
DevOpsSchool.com	DevOps engineers, SREs, platform teams, cloud beginners	DevOps + cloud operations; may include Google Cloud networking fundamentals	Check website	https://www.devopsschool.com/
ScmGalaxy.com	Students and early-career engineers	SCM/DevOps foundations; may include cloud and automation topics	Check website	https://www.scmgalaxy.com/
CLoudOpsNow.in	Cloud operations and platform teams	CloudOps practices, operations, monitoring, reliability	Check website	https://www.cloudopsnow.in/
SreSchool.com	SREs and reliability-focused engineers	SRE practices, incident response, monitoring, reliability engineering	Check website	https://www.sreschool.com/
AiOpsSchool.com	Ops teams adopting AIOps	AIOps concepts, automation for operations, observability	Check website	https://www.aiopsschool.com/

19. Top Trainers

Platform/Site	Likely Specialization	Suitable Audience	Website URL
RajeshKumar.xyz	Cloud/DevOps training content (verify specific topics on site)	Individuals seeking guided training	https://rajeshkumar.xyz/
devopstrainer.in	DevOps training services (verify catalog)	DevOps engineers, SREs, platform teams	https://www.devopstrainer.in/
devopsfreelancer.com	Freelance DevOps enablement (verify offerings)	Teams needing short-term expert help	https://www.devopsfreelancer.com/
devopssupport.in	DevOps support/training (verify scope)	Ops teams needing practical troubleshooting and support	https://www.devopssupport.in/

20. Top Consulting Companies

Company	Likely Service Area	Where They May Help	Consulting Use Case Examples	Website URL
cotocus.com	Cloud/DevOps consulting (verify service lines)	Architecture, implementation support, migrations	Designing hybrid connectivity patterns; setting up IaC; operational runbooks	https://cotocus.com/
DevOpsSchool.com	DevOps and cloud consulting (verify service lines)	Platform engineering, DevOps transformation, training + advisory	Standardizing network governance; enabling CI/CD for infra; operational maturity	https://www.devopsschool.com/
DEVOPSCONSULTING.IN	DevOps consulting (verify scope)	DevOps automation and cloud operations	Cloud adoption planning; automation pipelines; operational monitoring setup	https://www.devopsconsulting.in/

21. Career and Learning Roadmap

What to learn before Network Connectivity Center

To be successful with NCC on Google Cloud Networking, learn:

VPC fundamentals
Subnets, routes, firewall rules, private IP design
Hybrid connectivity basics
Cloud VPN / HA VPN concepts
Interconnect basics (Dedicated vs Partner)
Dynamic routing
BGP concepts (ASN, route advertisement, MED/localpref basics)
Cloud Router operations
Security basics
IAM fundamentals and least privilege
Network segmentation principles
Troubleshooting tools
VPC Flow Logs, traceroute, ping, TCP tests
Network Intelligence Center connectivity tests (recommended)

What to learn after Network Connectivity Center

Advanced segmentation and routing policy (route control features, if available)
Network security architectures:
Inspection insertion patterns
Cloud NGFW options and third-party firewalls
Multi-region hybrid design and failover testing
Infrastructure as Code for networking (Terraform modules, CI/CD)
Governance at scale:
Org policies, folder/project structure, shared VPC design

Job roles that use it

Cloud Network Engineer
Platform Engineer (networking-heavy)
Site Reliability Engineer (hybrid operations)
Cloud Solutions Architect
Security Engineer (network segmentation/governance)
Network Architect (WAN modernization)

Certification path (if available)

Google Cloud certifications change over time; commonly relevant certifications include: – Professional Cloud Network Engineer – Professional Cloud Architect – Associate Cloud Engineer

Verify current certification offerings here:
https://cloud.google.com/learn/certification

Project ideas for practice

Build a two-hub model (prod/non-prod) with strict separation and documented route exchange.
Simulate branch connectivity using HA VPN and Cloud Router with dynamic routing and failover tests.
Build a shared services connectivity domain and test least-privilege routing to only required services.
Automate hub/spoke creation using Terraform and enforce guardrails with policy checks.
Create an operational dashboard: – VPN tunnel health – BGP session status – Flow log sampling for key paths

22. Glossary

Network Connectivity Center (NCC): Google Cloud service to manage hub-and-spoke connectivity and route exchange across networks.
Hub: The central NCC resource representing a connectivity domain.
Spoke: An attachment to a hub representing a network endpoint (VPN, Interconnect attachment, router appliance, or VPC where supported).
VPC (Virtual Private Cloud): A logically isolated network in Google Cloud.
Subnet: A CIDR range within a VPC in a specific region.
Route exchange / propagation: Sharing routes learned from one spoke to other spokes via the hub.
Cloud Router: Managed BGP router for dynamic routing with VPN/Interconnect/router appliances.
BGP (Border Gateway Protocol): Routing protocol used for exchanging routes dynamically between networks.
ASN (Autonomous System Number): Identifier used in BGP.
HA VPN: High availability Cloud VPN, typically using redundant tunnels and Cloud Router.
Cloud Interconnect: Private connectivity between on-prem and Google Cloud (Dedicated or Partner).
VLAN attachment: A logical attachment for Interconnect connectivity into a VPC via Cloud Router.
Router appliance: A virtual or physical routing device (often third-party) that can participate in BGP and routing policies.
Transitive routing: Traffic can flow from one network to another through an intermediate connectivity domain (hub), not just direct peers.
VPC firewall rules: Stateful rules controlling ingress/egress traffic to VM instances in a VPC.
VPC Flow Logs: Logs of network flows for troubleshooting and security analytics.
Cloud Audit Logs: Logs recording administrative actions and access patterns for Google Cloud resources.
Network Intelligence Center: Google Cloud suite for network observability (topology, connectivity tests, performance).

23. Summary

Network Connectivity Center is Google Cloud’s centralized hub-and-spoke service for managing hybrid and multi-network connectivity in the Networking category. It helps you scale beyond point-to-point VPNs and peering meshes by attaching networks as spokes to a hub and coordinating route exchange so connectivity is consistent and governable.

Key takeaways: – Where it fits: NCC sits above Cloud VPN, Interconnect, Cloud Router, and VPC routing to provide a scalable connectivity model. – Cost: Expect costs driven by spoke count, traffic volume (if data processing is billed), and underlying services (VPN/Interconnect, egress, logging). – Security: NCC is not a firewall—use segmentation (separate hubs or route controls), least-privilege IAM, and strong firewall/inspection patterns. – When to use: Choose NCC when you have many networks/sites/VPCs and need centralized governance and scalable routing. – Next learning step: Deepen your hybrid routing skills with Cloud Router + BGP, then practice troubleshooting with Network Intelligence Center and VPC Flow Logs using controlled labs.

rajeshkumar

Category

1. Introduction

What this service is

One-paragraph simple explanation

One-paragraph technical explanation

What problem it solves

2. What is Network Connectivity Center?

Official purpose

Core capabilities

Major components

Service type

Scope: regional/global and resource boundaries

How it fits into the Google Cloud ecosystem

3. Why use Network Connectivity Center?

Business reasons

Technical reasons

Operational reasons

Security/compliance reasons

Scalability/performance reasons

When teams should choose it

When they should not choose it

4. Where is Network Connectivity Center used?

Industries

Team types

Workloads

Architectures

Real-world deployment contexts

Production vs dev/test usage

5. Top Use Cases and Scenarios

1) Central hub for many on-prem sites using HA VPN

2) Central hub for Dedicated/Partner Interconnect VLAN attachments

3) Connect third-party router appliances to Google Cloud for advanced routing

4) Multi-VPC connectivity without peering sprawl (where VPC spokes are supported)

5) Controlled transitive routing (site A ↔ site B via cloud)

6) Segmented connectivity domains (prod vs non-prod)

7) Gradual migration from legacy WAN to cloud-based connectivity

8) Centralized governance for network changes

9) Standard pattern for M&A network integration

10) Multi-region hybrid architecture with consistent routing

11) Central hub for shared services + data platform access

12) Operational visibility and troubleshooting standardization

6. Core Features

Hub-and-spoke connectivity model

Spoke types for hybrid connectivity

Centralized route exchange (transitive routing)

Routing policy controls (route tables / selective exchange)

Integration with Cloud Router and BGP

Centralized connectivity operations (control plane)

Works with Google Cloud’s global network (via underlying transports)

IAM-based governance

7. Architecture and How It Works

High-level architecture

Control flow vs data flow

Integrations with related services

Dependency services

Security/authentication model

Networking model considerations

Monitoring/logging/governance considerations

Simple architecture diagram (conceptual)

Production-style architecture diagram (hybrid + segmentation)

8. Prerequisites

Account/project requirements

Permissions / IAM roles

Billing requirements

CLI/SDK/tools

Region availability

Quotas/limits

Prerequisite services/APIs

9. Pricing / Cost

Pricing dimensions (typical model)

Free tier

Key cost drivers

Hidden or indirect costs to plan for

Network/data transfer implications

How to optimize cost

Example low-cost starter estimate (conceptual)

Example production cost considerations

10. Step-by-Step Hands-On Tutorial

Objective

Lab Overview