Cannot connect from Compute Engine instance to Cloud SQL via Private IP

In this configuration I have a Compute Engine instance in GCP running Windows Server 2019. I have two network adapters; one that is connected to the public network, and one that is connected to an internal virtual network called DMZ. I then have a Cloud SQL instance running SQL Server, also configured with Private IP and running on the virtual network called DMZ.

However, I am not able to actually connect to the IP address of the Cloud SQL instance using SQL Server Management Studio from the Compute Engine node.

Here are some additional details:

  • VM is connected to two networks: default with a 172... IP, and dmz with a 10.142... IP; OS is Windows Server 2019
  • Cloud SQL has a Private IP only, connected to dmz with a 10.52... IP; running SQL Server 2017 Web
  • VPC Network dmz has Private Service Connection created with 10.52... IP range
  • VPC Network default is stock, no modifications
  • All resources are in the same region (US-East-1)
  • tracert from VM to Cloud SQL fails/times out

How does one go about enabling access? I have followed all the steps and can't get it to work so any help would be greatly appreciated.


Solution 1:

It turns out that the problem was caused by having two NICs. Once I made a new VM with only one NIC it was fine.