Question

Difficulty: MediumDeploying Cloud Load Balancers and Configuring Cloud DNS

Your organization is integrating an on-premises data center with a Google Cloud Virtual Private Cloud (VPC) network over Cloud Interconnect. You need to enable on-premises clients to resolve internal Cloud DNS zone records ending in `internal.example.com`. Place the deployment steps in the correct chronological order from first to last to complete this configuration.

  1. 1Create a Cloud DNS server policy on the VPC network with the inbound DNS forwarding feature enabled.
  2. 2Retrieve the reserved inbound DNS forwarder IP addresses assigned to the VPC subnets.
  3. 3Configure the on-premises DNS server conditional forwarders to direct queries for `internal.example.com` to the retrieved Cloud DNS inbound forwarder IP addresses.
  4. 4Execute a DNS query from an on-premises client host to verify internal record resolution for a host in `internal.example.com`.

Answer

The correct sequence starts by enabling inbound DNS forwarding via a Cloud DNS server policy on the VPC network, retrieving the allocated inbound forwarder IP addresses, configuring on-premises DNS conditional forwarding to those IP addresses, and finally testing resolution from an on-premises host.
Configuring hybrid DNS resolution requires provisioning the cloud infrastructure first (Cloud DNS server policy with inbound forwarding), identifying the generated inbound forwarder IP addresses, configuring the on-premises DNS server to use those IPs as conditional forwarders, and finally verifying connectivity from an on-premises client.

Step-by-Step Solution

1
Enable inbound DNS forwarding on the VPC network.
A Cloud DNS server policy is created on the VPC network, provisioning inbound DNS forwarder entry points.
Cloud DNS cannot accept external/on-premises DNS queries until inbound forwarding is explicitly enabled via a server policy.
2
Look up the allocated Cloud DNS inbound forwarder IP addresses.
The administrator obtains the specific internal IP addresses created in the VPC subnets for inbound DNS traffic.
These IP addresses serve as the target destinations for DNS queries originating from the on-premises network.
3
Update on-premises DNS conditional forwarding rules.
The on-premises DNS servers forward all requests for `internal.example.com` across the hybrid connection to Google Cloud.
On-premises clients send queries to their local DNS server, which requires conditional forwarding rules pointing to the Cloud DNS forwarders.
4
Test end-to-end resolution from an on-premises client.
Successful DNS response containing the private IP address of the queried Google Cloud resource.
Testing from the end client verifies that routing, firewall rules, and DNS forwarding configurations are operating correctly.

Key Concept

Cloud DNS Inbound Forwarding Configuration for Hybrid Cloud Environments
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