Cloud VPN

Cloud VPN allows you to connect to your Virtual Private Cloud (VPC) network from your existing network, such as your on-premises network, another VPC network, or another cloud provider’s network, through an IPsec connection using (i) Classic VPN, which supports dynamic (BGP) routing or static routing (route-based or policy-based), or (ii) HA (high-availability) VPN, which supports dynamic routing with a simplified redundancy setup, separate failure domains for the gateway interfaces, and a higher service level objective.

Google Cloud Hybrid Connectivity

~ Last updated on : ~ jayendrapatil

Google Cloud Hybrid Connectivity

Google Cloud provides various network connectivity options to meet the needs, using either public networks, peering, or interconnect technologies

Google Cloud Hybrid Connectivity Options

Public Network Connectivity

Standard internet connection can be used to connect Google Cloud with the on-premises environment if it meets the bandwidth needs.

Cloud VPN

  • provides secure, private connectivity using IPSec
  • connects on-premises networks to VPC or two VPCs in GCP
  • traffic flows via the VPN tunnel but is still routed over the public internet
  • traffic is encrypted by one gateway and decrypted by the other
  • allows users to access private RFC1918 addresses on resources in the VPC from on-prem computers also using private RFC1918 addresses.
  • can be used with Private Google Access for on-premises hosts
  • provides guaranteed uptime of 99.99% using High availability VPN
  • supports only site-to-site VPN
  • supports up to 3Gbps per tunnel with a maximum of 8 tunnels
  • supports static as well as dynamic routing using Cloud Router
  • supports IKEv1 or IKEv2 using a shared secret

Peering

  • Peering provides better connectivity to Google Cloud as compared to the public connection. However, the connectivity is still not RFC1918-to-RFC1918 private address connectivity.
  • Peering gets your network as close as possible to Google Cloud public IP addresses.

Direct Peering

  • requires you to lease co-lo space and install and support routing equipment in a Google Point Of Presence (PoP).
  • supports BGP over a link to exchange network routes.
  • All traffic destined to Google rides over this new link, while traffic to other sites on the internet rides your regular internet connection.

Carrier Peering

  • preferred if installing equipment isn’t an option or would prefer to work with a service provider partner as an intermediary to peer with Google
  • connection to Google is via a new link connection installed to a partner carrier that is already connected to the Google network itself.
  • supports BGP or uses static routing over that link.
  • All traffic destined to Google rides over this new link.
  • Traffic to other sites on the internet rides your regular internet connection.

Interconnect

  • Interconnects are similar to peering in that the connections get your network as close as possible to the Google network.
  • Interconnects differ from peering as they provide connectivity using private address space into the Google VPC.
  • For RFC1918-to-RFC1918 private address connectivity, either a dedicated or partner interconnect is required

Dedicated Interconnect

  • provides private, high-performance connectivity to Google Cloud
  • requires you to lease co-lo space and install and support routing equipment in a Google Point Of Presence (PoP).
  • requires installing a link directly to Google by choosing a 10 Gbps or 200 Gbps pipe and provisioning a VLAN attachment over the physical link
  • gives the RFC1918-to-RFC1918 private address connectivity.
  • All traffic destined to the Google Cloud VPC rides over this new link.
  • Traffic to other sites on the internet rides the regular internet connection.
  • Single Interconnect connection does not offer HA and GCP recommends redundancy using 2 (99.9%) or 4 (99.99%) interconnect connections so that if one connection fails, the other connection can continue to serve traffic

Partner Interconnect

  • provides private, high-performance connectivity to Google Cloud
  • preferred if bandwidth requires are below 10 Gbps or installing equipment isn’t an option or would prefer to work with a service provider partner as an intermediary
  • similar to carrier peering in that you connect to a partner service provider that is directly connected to Google.
  • supports BGP or use static routing over that link.
  • requires provisioning a VLAN attachment over the physical link
  • gives the RFC1918-to-RFC1918 private address connectivity.
  • All traffic destined to your Google VPC rides over this new link.
  • Traffic to other sites on the internet rides your regular internet connection.

Google Cloud Hydrid Connectivity Decision Tree

Google Cloud Hydrid Connectivity Decision Tree

Google Cloud Hybrid Connectivity

Google Cloud Data Transfer Services Overview

~ Last updated on : ~ jayendrapatil

Google Cloud Data Transfer Services

Google Cloud Data Transfer services provide various options in terms of network and transfer tools to help transfer data from on-premises to Google Cloud network.

📋 Last Updated: June 2026 — Updated with gcloud storage CLI (gsutil replacement), Storage Transfer Service event-driven transfers, Cross-Cloud Interconnect, Transfer Appliance data export, BigQuery Data Transfer Service new sources, Classic VPN dynamic routing deprecation, and Network Connectivity Center.

Network Services

Cloud VPN

  • Provides network connectivity with Google Cloud between on-premises network and Google Cloud, or from Google Cloud to another cloud provider.
  • Cloud VPN still routes the traffic through the Internet.
  • Cloud VPN is quick to set up (as compared to Interconnect)
  • Each Cloud VPN tunnel can support up to 3 Gbps total for ingress and egress, but available bandwidth depends on the connectivity. Bandwidth can be increased by adding more tunnels.
  • Choose Cloud VPN to encrypt traffic to Google Cloud, or with lower throughput solution, or experimenting with migrating the workloads to Google Cloud
  • HA VPN is the recommended VPN configuration offering a 99.99% SLA when configured with tunnels on both interfaces per Google best practices.
  • Classic VPN provides a 99.9% SLA. Note: Classic VPN dynamic routing (BGP) was deprecated on August 1, 2025. HA VPN must be used for BGP-based VPN connectivity.
  • HA VPN over Cloud Interconnect allows encrypting traffic traversing Dedicated or Partner Interconnect connections for additional security and compliance.
  • Cloud VPN supports customizable cipher options (Public Preview as of June 2025) allowing configuration of ciphers per security requirements.
  • Cloud Interconnect offers a direct connection to Google Cloud through Google or one of the Cloud Interconnect service providers.
  • Cloud Interconnect service prevents data from going on the public internet and can provide a more consistent throughput for large data transfers
  • For enterprise-grade connection to Google Cloud that has higher throughput requirements, choose Dedicated Interconnect (10 Gbps to 100 Gbps) or Partner Interconnect (50 Mbps to 50 Gbps)
  • Cloud Interconnect provides access to all Google Cloud products and services from your on-premises network except Google Workspace.
  • Cloud Interconnect also allows access to supported APIs and services by using Private Google Access from on-premises hosts.
  • Cross-Cloud Interconnect enables dedicated, private connectivity between Google Cloud and another cloud service provider (AWS, Azure, Oracle Cloud Infrastructure, Alibaba Cloud). This eliminates the need for traffic to traverse the public internet for multicloud architectures.
  • Partner Cross-Cloud Interconnect (available for AWS) provides an on-demand method for cross-cloud transport without manually setting up networking components.
  • Cross-Site Interconnect (GA 2025) is a transparent, on-demand Layer 2 connectivity solution leveraging Google’s global infrastructure for high-bandwidth connectivity between on-premises sites.
  • Direct Peering provides access to the Google network with fewer network hops than with a public internet connection
  • By using Direct Peering, internet traffic is exchanged between the customer network and Google’s Edge Points of Presence (PoPs), which means the data does not use the public internet.
  • Google does not offer a Service Level Agreement (SLA) with Direct Peering.
  • For SLA-backed connectivity, Cloud Interconnect (Dedicated or Partner) is recommended over Direct Peering.

Network Connectivity Center

  • Network Connectivity Center (NCC) is an orchestration framework that simplifies network connectivity using a hub-and-spoke model.
  • Supports three types of spokes: VPC spokes, Producer VPC spokes, and Hybrid spokes (HA VPN tunnels, Cloud Interconnect VLAN attachments, Router appliance VMs).
  • Enables site-to-cloud connectivity (external networks to Google Cloud) and site-to-site connectivity (using Google Cloud as enterprise WAN).
  • Supports up to 250 VPC spokes per hub and provides transitivity between workload VPCs.
  • Useful for managing complex multicloud and hybrid network topologies centrally.

Google Cloud Networking Services Decision Tree

Google Cloud Hybrid Connectivity

Transfer Services

gcloud storage (formerly gsutil)

⚠️ gsutil Deprecation Notice: gsutil is no longer the recommended CLI for Cloud Storage. Google recommends using gcloud storage commands in the Google Cloud CLI instead. gsutil does not support newer Cloud Storage features such as soft delete and managed folders. gcloud storage commands require less manual optimization and provide faster transfer rates.
  • gcloud storage (replacement for gsutil) is the standard tool for small- to medium-sized transfers (less than 1 TB) over a typical enterprise-scale network, from a private data center to Google Cloud.
  • gcloud storage provides all the basic features needed to manage Cloud Storage instances, including copying data to and from the local file system and Cloud Storage.
  • gcloud storage can also move, rename, and remove objects and perform real-time incremental syncs (similar to rsync) to a Cloud Storage bucket.
  • gcloud storage is especially useful in the following scenarios:
    • As-needed transfers or during command-line sessions by your users.
    • Transferring only a few files or very large files, or both.
    • Consuming the output of a program (streaming output to Cloud Storage).
    • Watching a directory with a moderate number of files and syncing any updates with very low latencies.
  • gcloud storage provides the following features:
    • Parallel multi-threaded transfers for increased transfer speeds.
    • Composite transfers for a single large file, breaking them into smaller chunks to increase transfer speed. Chunks are transferred and validated in parallel. Once the chunks arrive at Google, they are combined (composited) to form a single object.
    • Uses faster CRC32C hashing algorithm for data integrity checking (improved over gsutil’s crcmod).
  • Migration: Replace gsutil commands with equivalent gcloud storage commands. For example: gsutil cp → gcloud storage cp, gsutil rsync → gcloud storage rsync.
  • Storage Transfer Service is a fully managed, highly scalable service to automate transfers into Cloud Storage from multiple sources.
  • Supported Sources:
    • Amazon S3
    • S3-compatible storage (requires agents)
    • Microsoft Azure Blob Storage and Azure Data Lake Storage Gen2
    • Cloud Storage (bucket-to-bucket)
    • Publicly accessible HTTP/HTTPS URLs
    • On-premises file systems (POSIX-compliant, requires agents)
    • Hadoop Distributed File System (HDFS, requires agents)
  • Storage Transfer Service for Cloud-to-Cloud transfers:
    • Supports transfers from S3, Azure Blob Storage, and Cloud Storage without agents.
    • Supports daily copies of any modified objects.
  • Storage Transfer Service for on-premises data:
    • Is designed for large-scale transfers (up to petabytes of data, billions of files).
    • Supports full copies or incremental copies.
    • Can be set up by installing on-premises software (known as agents) onto computers in the data center.
  • Has a simple, managed graphical user interface; even non-technically savvy users (after setup) can use it to move data.
  • Provides robust error-reporting and a record of all files and objects that are moved.
  • Supports executing recurring transfers on a schedule.
  • Event-Driven Transfers (2025-2026):
    • Listens to event notifications to automatically transfer new or updated objects.
    • Supported for AWS S3 (via S3 Event Notifications to Amazon SQS).
    • Supported for Azure Blob Storage and Data Lake Storage Gen2 (via Azure Event Grid to Azure Storage Queues) — available since January 2026.
    • Supported for Cloud Storage (via Pub/Sub notifications).
  • Private Network Transfers (December 2025): Transfer data from AWS S3 or Azure Blob Storage to Cloud Storage over a private network connection using Cross-Cloud Interconnect or Partner Interconnect, optimizing costs and compliance.
  • Google-Managed Private Network for S3: Transfer from S3 over a Google-managed private network, eliminating AWS egress fees with a flat per-GiB rate.
  • AWS GovCloud Support (2026): Supports transfers from S3 buckets in us-gov-east-1 and us-gov-west-1 regions.
  • Organization Policy Constraints (February 2026): Custom organization policy constraints to control Storage Transfer Service usage (e.g., restrict sources or destinations).
  • Encrypts data in transit, supports VPC Service Controls, and uses checksums for data integrity.

Transfer Appliance

  • Transfer Appliance is an excellent option for performing large-scale transfers, especially when a fast network connection is unavailable, it’s too costly to acquire more bandwidth, or it’s a one-time transfer.
  • Expected turnaround time for a network appliance to be shipped, loaded with the data, shipped back, and rehydrated on Google Cloud is approximately 50 days.
  • Consider Transfer Appliance if the online transfer timeframe is calculated to be substantially more than this timeframe.
  • Transfer Appliance requires the ability to receive and ship back the Google-owned hardware.
  • Transfer Appliance is available only in certain countries.
  • Data Export (GA in US): Transfer Appliance now supports exporting data from Cloud Storage to the appliance, which is then shipped to you. This enables large-scale data egress from Google Cloud when network transfer is impractical.
  • gcloud CLI Support (Alpha): gcloud alpha transfer appliances commands allow viewing in-progress results, working with draft orders, and cloning existing orders.
  • Data is encrypted during upload, transit, after upload to Cloud Storage, and during download for data export.

BigQuery Data Transfer Service

  • BigQuery Data Transfer Service automates data movement into BigQuery on a scheduled, managed basis.
  • After a data transfer is configured, the BigQuery Data Transfer Service automatically loads data into BigQuery on a regular basis.
  • BigQuery Data Transfer Service can also initiate data backfills to recover from any outages or gaps.
  • BigQuery Data Transfer Service can only sink data to BigQuery and cannot be used to transfer data out of BigQuery.
  • Also supports dataset copies and scheduled queries within BigQuery.
  • BigQuery Data Transfer Service supports loading data from the following data sources:
    • Google SaaS Applications:
      • Google Ads
      • Google Ad Manager
      • Campaign Manager
      • Search Ads 360
      • Google Merchant Center
      • Google Play
      • YouTube Channel reports
      • YouTube Content Owner reports
      • Google Analytics 4 (GA4) — provides 12 daily partitioned tables reflecting UI reports
    • Cloud Storage — supports incremental and truncated write preferences
    • External cloud storage providers:
      • Amazon S3 (supports cross-cloud transfer)
    • Data warehouses:
      • Teradata
      • Amazon Redshift
    • Third-party connectors (2025):
      • Salesforce Sales Cloud
      • Salesforce Marketing Cloud (SFMC)
      • Facebook Ads
      • Adobe Analytics

Transfer Data vs Speed Comparison

Data Migration Speeds

Choosing the Right Transfer Method

Method Best For Data Size Network Requirement
gcloud storage Ad-hoc, small transfers < 1 TB Standard internet
Storage Transfer Service Recurring, large cloud-to-cloud or on-premises transfers TB to PB scale Available network (supports private network)
Transfer Appliance One-time massive transfers, limited bandwidth Hundreds of TB to PB Minimal (physical shipping)
BigQuery Data Transfer Service SaaS data ingestion into BigQuery Varies Standard internet

GCP Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • GCP services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • GCP exam questions are not updated to keep up the pace with GCP updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. A company wants to connect cloud applications to an Oracle database in its data center. Requirements are a maximum of 9 Gbps of data and a Service Level Agreement (SLA) of 99%. Which option best suits the requirements?
    1. Implement a high-throughput Cloud VPN connection
    2. Cloud Router with VPN
    3. Dedicated Interconnect
    4. Partner Interconnect
  2. An organization wishes to automate data movement from Software as a Service (SaaS) applications such as Google Ads and Google Ad Manager on a scheduled, managed basis. This data is further needed for analytics and generate reports. How can the process be automated?
    1. Use Storage Transfer Service to move the data to Cloud Storage
    2. Use Storage Transfer Service to move the data to BigQuery
    3. Use BigQuery Data Transfer Service to move the data to BigQuery
    4. Use Transfer Appliance to move the data to Cloud Storage
  3. Your company’s migration team needs to transfer 1PB of data to Google Cloud. The network speed between the on-premises data center and Google Cloud is 100Mbps. The migration activity has a timeframe of 6 months. What is the efficient way to transfer the data?
    1. Use BigQuery Data Transfer Service to transfer the data to Cloud Storage
    2. Expose the data as a public URL and Storage Transfer Service to transfer it
    3. Use Transfer Appliance to transfer the data to Cloud Storage
    4. Use gcloud storage command to transfer the data to Cloud Storage
  4. Your company uses Google Analytics for tracking. You need to export the session and hit data from a Google Analytics 360 reporting view on a scheduled basis into BigQuery for analysis. How can the data be exported?
    1. Configure a scheduler in Google Analytics to convert the Google Analytics data to JSON format, then import directly into BigQuery using bq command line.
    2. Use gcloud storage to export the Google Analytics data to Cloud Storage, then import into BigQuery and schedule it using Cron.
    3. Import data to BigQuery directly from Google Analytics using Cron
    4. Use BigQuery Data Transfer Service to import the data from Google Analytics
  5. A company needs to automatically transfer new files from an AWS S3 bucket to Cloud Storage as soon as they are created, with minimal latency. What is the most efficient approach?
    1. Schedule Storage Transfer Service to run every 15 minutes
    2. Use a Lambda function to call the Cloud Storage API on each new object
    3. Configure Storage Transfer Service event-driven transfers using S3 Event Notifications and Amazon SQS
    4. Use gsutil rsync with a cron job
  6. An organization wants to establish private, high-bandwidth connectivity between their Google Cloud environment and their AWS infrastructure for a multicloud application. Which service should they use?
    1. Cloud VPN with HA configuration
    2. Partner Interconnect
    3. Cross-Cloud Interconnect
    4. Direct Peering
  7. A company needs to transfer 500 TB of data from Azure Blob Storage to Cloud Storage while keeping all traffic off the public internet and maintaining dedicated bandwidth. What combination should they use?
    1. Storage Transfer Service over public internet
    2. Storage Transfer Service with private network transfer over Cross-Cloud Interconnect
    3. Transfer Appliance
    4. gcloud storage cp command
  8. Your organization wants to centrally manage connectivity between multiple VPC networks, on-premises sites, and other cloud providers using a hub-and-spoke model. Which Google Cloud service should you use?
    1. Cloud Router
    2. VPC Network Peering
    3. Shared VPC
    4. Network Connectivity Center

References

 

Google Cloud VPN

~ Last updated on : ~ jayendrapatil

Google Cloud VPN

  • Cloud VPN securely connects your peer network to the Virtual Private Cloud (VPC) network through an IPsec VPN connection.
  • Traffic traveling between the two networks is encrypted by one VPN gateway and then decrypted by the other VPN gateway.
  • Cloud VPN protects the data as it travels over the internet.
  • Two instances of Cloud VPN can also be connected to each other.

Cloud VPN Specifications

  • only supports site-to-site IPsec VPN connectivity
  • does not support client-to-gateway scenarios i.e. Cloud VPN doesn’t support use cases where client computers need to “dial in” to a VPN by using client VPN software.
  • only supports IPsec. Other VPN technologies (such as SSL VPN) are not supported.
  • can be used with Private Google Access for on-premises hosts
  • Each Cloud VPN gateway must be connected to another Cloud VPN gateway or a peer VPN gateway.
  • Peer VPN gateway must have a static external (internet routable) IPv4 address, needed to configure Cloud VPN.
  • requires that the peer VPN gateway be configured to support prefragmentation. Packets must be fragmented before being encapsulated.
  • Each Cloud VPN tunnel can support up to 3 Gbps total for ingress and egress
  • Cloud VPN only supports a pre-shared key for authentication. Cloud VPN supports IKEv1 and IKEv2 by using an IKE pre-shared key (shared secret) and IKE ciphers.

Cloud VPN Components

Google Cloud VPN Components

  • Cloud VPN gateway
    • A virtual VPN gateway running in Google Cloud managed by Google, using a specified configuration in the project, and used only by you.
    • Each Cloud VPN gateway is a regional resource that uses one or more regional external IP addresses.
    • A Cloud VPN gateway can connect to a peer VPN gateway.
  • Peer VPN gateway
    • A gateway that is connected to a Cloud VPN gateway.
    • A peer VPN gateway can be one of the following:
      • Another Cloud VPN gateway
      • A VPN gateway hosted by another cloud provider such as AWS or Microsoft Azure
      • An on-premises VPN device or VPN service
  • External VPN gateway
    • A gateway resource configured for HA VPN that provides information to Google Cloud about the peer VPN gateway or gateways.
  • Remote peer IP address
    • For an HA VPN gateway interface that connects to an external VPN gateway, the remote peer IP address is the IP address of the interface on the external VPN gateway that is used for the tunnel.
  • VPN tunnel
    • A VPN tunnel connects two VPN gateways and serves as a virtual medium through which encrypted traffic is passed.
  • Internet Key Exchange (IKE)
    • IKE is the protocol used for authentication and to negotiate a session key for encrypting traffic.

Classic VPN

  • Classic VPN gateways have a single interface, a single external IP address, and support tunnels that use dynamic (BGP) or static routing (policy-based or route-based).
  • Classic VPN provides an SLA of 99.9% service availability.
  • Circa Oct 2021, Classic VPN would be deprecated

Cloud VPN HA

  • Cloud VPN HA provides a highly available and secure connection between the on-premises and the VPC network through an IPsec VPN connection in a single region
  • HA VPN provides an SLA of 99.99% service availability, when configured with two interfaces and two external IP addresses.
  • Cloud VPN supports the creation of multiple HA VPN gateways and each of the HA VPN gateway interfaces supports multiple tunnels
  • Peer VPN gateway device must support dynamic (BGP) routing.
  • To achieve high availability when both VPN gateways are located in VPC networks, two HA VPN gateways must be used, and both of them must be located in the same region.
  • Even though both gateways must be located in the same region, if the VPC network uses global dynamic routing mode, the routes to the subnets that the gateways share with each other can be located in any region

Google Cloud VPN HA

Active/Active vs Active/Passive Routing Options

  • If a Cloud VPN tunnel goes down, it restarts automatically.
  • If an entire virtual VPN device fails, Cloud VPN automatically instantiates a new one with the same configuration.
  • The new gateway and tunnel connect automatically.
  • Active/Active
    • Effective aggregate throughput is the combined throughput of both tunnels.
    • Peer gateway advertises the peer network’s routes with identical MED values for each tunnel.
    • Egress traffic sent to the peer network uses equal-cost multipath (ECMP) routing.
    • If one tunnel becomes unavailable, Cloud Router withdraws the learned custom dynamic routes whose next hops are the unavailable tunnel, which can take ~40 seconds
  • Active/Passive
    • Effective aggregate throughput is the individual throughput of each tunnel
    • Peer gateway advertises the peer network’s routes with different MED values for each tunnel.
    • Egress traffic sent to the peer network uses the route with the highest priority, as long as the associated tunnel is available.
    • Peer gateway can only use the tunnel with the highest priority to send traffic to Google Cloud.
    • If one tunnel becomes unavailable, Cloud Router withdraws the learned custom dynamic routes whose next hops are the unavailable tunnel, which can take ~40 seconds
  • Google Cloud recommends
    • Using Active/Passive configuration with a single HA VPN Gateway as the observed bandwidth capacity at the time of normal tunnel operation matches the bandwidth capacity observed during failover
    • Using Active/Active configuration with multiple HA VPN Gateways as the observed bandwidth capacity at the time of normal tunnel operation is twice that of the guaranteed bandwidth capacity

Classic VPN vs HA VPN

Google Cloud Classic VPN vs HA VPN

GCP Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • GCP services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • GCP exam questions are not updated to keep up the pace with GCP updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. Your company’s infrastructure is on-premises, but all machines are running at maximum capacity. You want to burst to Google
    Cloud. The workloads on Google Cloud must be able to directly communicate to the workloads on-premises using a private IP
    range. What should you do?

    1. In Google Cloud, configure the VPC as a host for Shared VPC.
    2. In Google Cloud, configure the VPC for VPC Network Peering.
    3. Create bastion hosts both in your on-premises environment and on Google Cloud. Configure both as proxy servers using
      their public IP addresses.
    4. Set up Cloud VPN between the infrastructure on-premises and Google Cloud.

Related Reads

References

Google Cloud Networking Services Cheat Sheet

~ Last updated on : ~ jayendrapatil

Virtual Private Cloud

  • Virtual Private Cloud (VPC) provides networking functionality for the cloud-based resources and services that is global, scalable, and flexible.
  • VPC networks are global resources, including the associated routes and firewall rules, and are not associated with any particular region or zone.
  • Subnets are regional resources and each subnet defines a range of IP addresses
  • Network firewall rules
    • control the Traffic to and from instances.
    • Rules are implemented on the VMs themselves, so traffic can only be controlled and logged as it leaves or arrives at a VM.
    • Firewall rules are defined to allow or deny traffic and are executed within order with a defined priority
    • Highest priority (lower integer) rule applicable to a target for a given type of traffic takes precedence
  • Resources within a VPC network can communicate with one another by using internal IPv4 addresses, subject to applicable network firewall rules.
  • Private access options for services allow instances with internal IP addresses can communicate with Google APIs and services.
  • Shared VPC to keep a VPC network in a common host project shared with service projects. Authorized IAM members from other projects in the same organization can create resources that use subnets of the Shared VPC network
  • VPC Network Peering allow VPC networks to be connected with other VPC networks in different projects or organizations.
  • VPC networks can be securely connected in hybrid environments by using Cloud VPN or Cloud Interconnect.
  • Primary and Secondary IP address cannot overlap with the on-premises CIDR
  • VPC networks only support IPv4 unicast traffic. They do not support broadcast, multicast, or IPv6 traffic within the network; VMs in the VPC network can only send to IPv4 destinations and only receive traffic from IPv4 sources.
  • VPC Flow Logs records a sample of network flows sent from and received by VM instances, including instances used as GKE nodes.

Cloud Load Balancing

  • Cloud Load Balancing is a fully distributed, software-defined managed load balancing service
  • distributes user traffic across multiple instances of the applications and reduces the risk that the of performance issues for the applications experience by spreading the load
  • provides health checking mechanisms that determine if backends, such as instance groups and zonal network endpoint groups (NEGs), are healthy and properly respond to traffic.
  • supports IPv6 clients with HTTP(S) Load Balancing, SSL Proxy Load Balancing, and TCP Proxy Load Balancing.
  • supports multiple Cloud Load Balancing types
    • Internal HTTP(S) Load Balancing
      • is a proxy-based, regional Layer 7 load balancer that enables running and scaling services behind an internal IP address.
      • supports a regional backend service, which distributes HTTP and HTTPS requests to healthy backends (either instance groups containing CE VMs or NEGs containing GKE containers).
      • supports path based routing
      • preserves the Host header of the original client request and also appends two IP addresses (Client and LB )to the X-Forwarded-For header
      • supports a regional health check that periodically monitors the readiness of the backends.
      • has native support for the WebSocket protocol when using HTTP or HTTPS as the protocol to the backend
    • External HTTP(S) Load Balancing
      • is a global, proxy-based Layer 7 load balancer that enables running and scaling the services worldwide behind a single external IP address
      • distributes HTTP and HTTPS traffic to backends hosted on Compute Engine and GKE
      • offers global (cross-regional) and regional load balancing
      • supports content-based load balancing using URL maps
      • preserves the Host header of the original client request and also appends two IP addresses (Client and LB) to the X-Forwarded-For header
      • supports connection draining on backend services
      • has native support for the WebSocket protocol when using HTTP or HTTPS as the protocol to the backend
      • does not support client certificate-based authentication, also known as mutual TLS authentication.
    • Internal TCP/UDP Load Balancing
      • is a managed, internal, pass-through, regional Layer 4 load balancer that enables running and scaling services behind an internal IP address
      • distributes traffic among VM instances in the same region in a Virtual Private Cloud (VPC) network by using an internal IP address.
      • provides high-performance, pass-through Layer 4 load balancer for TCP or UDP traffic.
      • routes original connections directly from clients to the healthy backends, without any interruption.
      • does not terminate SSL traffic and SSL traffic can be terminated by the backends instead of by the load balancer
      • provides access through VPC Network Peering, Cloud VPN or Cloud Interconnect
      • supports health check that periodically monitors the readiness of the backends.
    • External TCP/UDP Network Load Balancing
      • is a managed, external, pass-through, regional Layer 4 load balancer that distributes TCP or UDP traffic originating from the internet to among VM instances in the same region
      • Load-balanced packets are received by backend VMs with their source IP unchanged.
      • Load-balanced connections are terminated by the backend VMs. Responses from the backend VMs go directly to the clients, not back through the load balancer.
      • scope of a network load balancer is regional, not global. A network load balancer cannot span multiple regions. Within a single region, the load balancer services all zones.
      • supports connection tracking table and a configurable consistent hashing algorithm to determine how traffic is distributed to backend VMs.
      • does not support Network endpoint groups (NEGs) as backends
    • External SSL Proxy Load Balancing
      • is a reverse proxy load balancer that distributes SSL traffic coming from the internet to VM instances in the VPC network.
      • with SSL traffic, user SSL (TLS) connections are terminated at the load balancing layer, and then proxied to the closest available backend instances by using either SSL (recommended) or TCP.
      • supports global load balancing service with the Premium Tier
        supports regional load balancing service with the Standard Tier
      • is intended for non-HTTP(S) traffic. For HTTP(S) traffic, GCP recommends using HTTP(S) Load Balancing.
      • supports proxy protocol header to preserve the original source IP addresses of incoming connections to the load balancer
      • does not support client certificate-based authentication, also known as mutual TLS authentication.
    • External TCP Proxy Load Balancing
      • is a reverse proxy load balancer that distributes TCP traffic coming from the internet to VM instances in the VPC network
      • terminates traffic coming over a TCP connection at the load balancing layer, and then forwards to the closest available backend using TCP or SSL
      • use a single IP address for all users worldwide and automatically routes traffic to the backends that are closest to the user
      • supports global load balancing service with the Premium Tier
        supports regional load balancing service with the Standard Tier
      • supports proxy protocol header to preserve the original source IP addresses of incoming connections to the load balancer

Cloud CDN

  • caches website and application content closer to the user
  • uses Google’s global edge network to serve content closer to users, which accelerates the websites and applications.
  • works with external HTTP(S) Load Balancing to deliver content to the users
  • Cloud CDN content can be sourced from various types of backends
    • Instance groups
    • Zonal network endpoint groups (NEGs)
    • Serverless NEGs: One or more App Engine, Cloud Run, or Cloud Functions services
    • Internet NEGs, for endpoints that are outside of Google Cloud (also known as custom origins)
    • Buckets in Cloud Storage
  • Cloud CDN with Google Cloud Armor enforces security policies only for requests for dynamic content, cache misses, or other requests that are destined for the origin server. Cache hits are served even if the downstream Google Cloud Armor security policy would prevent that request from reaching the origin server.
  • recommends
    • using versioning instead of cache invalidation
    • using custom keys to improve cache hit ration
    • cache static content

Cloud VPN

  • securely connects the peer network to the VPC network or two VPCs in GCP through an IPsec VPN connection.
  • encrypts the data as it travels over the internet.
  • only supports site-to-site IPsec VPN connectivity and not client-to-gateway scenarios
  • allows users to access private RFC1918 addresses on resources in the VPC from on-prem computers also using private RFC1918 addresses.
  • can be used with Private Google Access for on-premises hosts
  • Cloud VPN HA
    • provides a high-available and secure connection between the on-premises and the VPC network through an IPsec VPN connection in a single region
    • provides an SLA of 99.99% service availability, when configured with two interfaces and two external IP addresses.
  • supports up to 3Gbps per tunnel with a maximum of 8 tunnels
  • supports static as well as dynamic routing using Cloud Router
  • supports IKEv1 or IKEv2 using a shared secret

Cloud Interconnect

  • Cloud Interconnect provides two options for extending the on-premises network to the VPC networks in Google Cloud.
  • Dedicated Interconnect (Dedicated connection)
    • provides a direct physical connection between the on-premises network and Google’s network
    • requires your network to physically meet Google’s network in a colocation facility with your own routing equipment
    • supports only dynamic routing
    • supports bandwidth to 10 Gbps minimum to 200 Gbps maximum.
  • Partner Interconnect (Use a service provider)
    • provides connectivity between the on-premises and VPC networks through a supported service provider.
    • supports bandwidth to 50 Mbps minimum to 10 Gbps maximum.
    • provides Layer 2 and Layer 3 connectivity
      • For Layer 2 connections, you must configure and establish a BGP session between the Cloud Routers and on-premises routers for each created VLAN attachment
      • For Layer 3 connections, the service provider establishes a BGP session between the Cloud Routers and their edge routers for each VLAN attachment.
  • Single Interconnect connection does not offer redundancy or high availability and its recommended to
    • use 2 in the same metropolitan area (city) as the existing one, but in a different edge availability domain (metro availability zone).
    • use 4 with 2 connections in two different metropolitan areas (city), and each connection in a different edge availability domain (metro availability zone)
    • Cloud Routers are required one in each Google Cloud region
  • Cloud Interconnect does not encrypt the connection between your network and Google’s network. For additional security, use application-level encryption or your own VPN.
  • Currently, Cloud VPN can’t be used with Dedicated Interconnect.

Cloud Router

  • is a fully distributed, managed service that provides dynamic routing and scales with the network traffic.
  • works with both legacy networks and VPC networks.
  • isn’t supported for Direct Peering or Carrier Peering connections.
  • helps dynamically exchange routes between the Google Cloud networks and the on-premises network.
  • peers with the on-premises VPN gateway or router to provide dynamic routing and exchanges topology information through BGP.
  • Google Cloud recommends creating two Cloud Routers in each region for a Cloud Interconnect for 99.99% availability.
  • supports following dynamic routing mode
    • Regional routing mode – provides visibility to resources only in the defined region.
    • Global routing mode – provides has visibility to resources in all regions

Cloud DNS

  • is a high-performance, resilient, reliable, low-latency, global DNS service that publishes the domain names to the global DNS in a cost-effective way.
  • With Shared VPC, Cloud DNS managed private zone, Cloud DNS peering zone, or Cloud DNS forwarding zone must be created in the host project
  • provides Private Zone which supports DNS services for a GCP project. VPCs in the same project can use the same name servers
  • supports DNS Forwarding for Private Zones, which overrides normal DNS resolution for the specified zones. Queries for the specified zones are forwarded to the listed forwarding targets.
  • supports DNS Peering, which allows sending requests for records that come from one zone’s namespace to another VPC network with GCP
  • supports DNS Outbound Policy, which forwards all DNS requests for a VPC network to the specified server targets. It disables internal DNS for the selected networks.
  • Cloud DNS VPC Name Resolution Order
    • DNS Outbound Server Policy
    • DNS Forwarding Zone
    • DNS Peering
    • Compute Engine internal DNS
    • Public Zones
  • supports DNSSEC, a feature of DNS, that authenticates responses to domain name lookups and protects the domains from spoofing and cache poisoning attacks