Configure connectivity using IP allowlists

Overview

Public IP connectivity is most appropriate when the source database is external to Google Cloud and has an externally accessible IPv4 address and TCP port. If the source database is hosted in another VPC in Google Cloud, then the easiest way to connect the source database with the Cloud SQL instance is by using VPC Peering.

You can test connectivity by adding another, temporary inbound firewall rule using the IP address of your local machine (or 0.0.0.0/0 to allow access from anywhere), and then running the following telnet command: telnet [SOURCE_DB_IP_ADDREESS] 1433. The connection should succeed. Delete the temporary firewall rule.