Azure SQL Database and Azure Synapse Analytics connectivity architecture
Applies to: Azure SQL Database Azure Synapse Analytics (dedicated SQL pool (formerly SQL DW) only)
This article explains architecture of various components that direct network traffic to a server in Azure SQL Database or dedicated SQL pools (formerly SQL DW) in Azure Synapse Analytics. It also explains different connection policies and how it impacts clients connecting from within Azure and clients connecting from outside of Azure.
- For settings that control connectivity to the logical server for Azure SQL Database and dedicated SQL pools (formerly SQL DW) in Azure Synapse Analytics, see connectivity settings.
- This article does not apply to Azure SQL Managed Instance. Refer to Connectivity architecture for Azure SQL Managed Instance.
The following diagram provides a high-level overview of the connectivity architecture.
The following steps describe how a connection is established to Azure SQL Database:
- Clients connect to the gateway that has a public IP address and listens on port 1433.
- The gateway, depending on the effective connection policy, redirects or proxies the traffic to the right database cluster.
- Inside the database cluster, traffic is forwarded to the appropriate database.
Servers in SQL Database and dedicated SQL pools (formerly SQL DW) in Azure Synapse support the following three options for the server's connection policy setting.
The connection policy for dedicated SQL pools (formerly SQL DW) in Azure Synapse Analytics is set to Default. You cannot change this for dedicated SQL pools in Synapse workspaces.
- Redirect (recommended): Clients establish connections directly to the node hosting the database, leading to reduced latency and improved throughput. For connections to use this mode, clients need to:
- Allow outbound communication from the client to all Azure SQL IP addresses in the region on ports in the range of 11000 to 11999. Use the Service Tags for SQL to make this easier to manage.
- Allow outbound communication from the client to Azure SQL Database gateway IP addresses on port 1433.
- When using the Redirect connection policy, refer to the Azure IP Ranges and Service Tags – Public Cloud for a list of your region's IP addresses to allow.
- Proxy: In this mode, all connections are proxied via the Azure SQL Database gateways, leading to increased latency and reduced throughput. For connections to use this mode, clients need to allow outbound communication from the client to Azure SQL Database gateway IP addresses on port 1433.
- When using the Proxy connection policy, refer to the Gateway IP addresses list later in this article for your region's IP addresses to allow.
- Default: This is the connection policy in effect on all servers after creation unless you explicitly alter the connection policy to either
Redirect. The default policy is
Redirectfor all client connections originating inside of Azure (for example, from an Azure Virtual Machine) and
Proxyfor all client connections originating outside (for example, connections from your local workstation).
We highly recommend the
Redirect connection policy over the
Proxy connection policy for the lowest latency and highest throughput. However, you will need to meet the additional requirements for allowing network traffic as outlined above. If the client is an Azure Virtual Machine, you can accomplish this using Network Security Groups (NSG) with service tags. If the client is connecting from a workstation on-premises then you may need to work with your network admin to allow network traffic through your corporate firewall.
Connections to private endpoint only support Proxy as the connection policy.
Connectivity from within Azure
If you are connecting from within Azure your connections have a connection policy of
Redirect by default. A policy of
Redirect means that after the TCP session is established to Azure SQL Database, the client session is then redirected to the right database cluster with a change to the destination virtual IP from that of the Azure SQL Database gateway to that of the cluster. Thereafter, all subsequent packets flow directly to the cluster, bypassing the Azure SQL Database gateway. The following diagram illustrates this traffic flow.
Connectivity from outside of Azure
If you are connecting from outside Azure, your connections have a connection policy of
Proxy by default. A policy of
Proxy means that the TCP session is established via the Azure SQL Database gateway and all subsequent packets flow via the gateway. The following diagram illustrates this traffic flow.
Open TCP ports 1434 and 14000-14999 to enable Connecting with DAC.
Gateway IP addresses
The table below lists the individual Gateway IP addresses and also Gateway IP address ranges per region.
Periodically, we will retire Gateways using old hardware and migrate the traffic to new Gateways as per the process outlined at Azure SQL Database traffic migration to newer Gateways. We strongly encourage customers to use the Gateway IP address subnets in order to not be impacted by this activity in a region.
- Logins for SQL Database or dedicated SQL pools (formerly SQL DW) in Azure Synapse can land on any of the Gateways in a region. For consistent connectivity to SQL Database or dedicated SQL pools (formerly SQL DW) in Azure Synapse, allow network traffic to and from ALL Gateway IP addresses and Gateway IP address subnets for the region.
- Use the Gateway IP addresses in this section if you're using a Proxy connection policy to connect to Azure SQL Database. If you're using the Redirect connection policy, refer to the Azure IP Ranges and Service Tags - Public Cloud for a list of your region's IP addresses to allow.
|Region name||Gateway IP addresses||Gateway IP address subnets|
|Australia Central||18.104.22.168, 22.214.171.124||126.96.36.199/29|
|Australia Central 2||188.8.131.52, 184.108.40.206||220.127.116.11/29|
|Australia East||18.104.22.168, 22.214.171.124, 126.96.36.199||188.8.131.52/29, 184.108.40.206/29, 220.127.116.11/29|
|Australia Southeast||18.104.22.168, 22.214.171.124, 126.96.36.199||188.8.131.52/29|
|Brazil South||184.108.40.206, 220.127.116.11, 18.104.22.168||22.214.171.124/29, 126.96.36.199/29|
|Canada Central||188.8.131.52, 184.108.40.206||220.127.116.11/29, 18.104.22.168/29, 22.214.171.124/29|
|Canada East||126.96.36.199, 188.8.131.52||184.108.40.206/29|
|Central US||220.127.116.11, 18.104.22.168||22.214.171.124/29, 126.96.36.199/29, 188.8.131.52/29|
|China East 2||184.108.40.206||220.127.116.11/29|
|China North 2||18.104.22.168||22.214.171.124/29|
|East Asia||126.96.36.199, 188.8.131.52, 184.108.40.206, 220.127.116.11||18.104.22.168/29, 22.214.171.124/29|
|East US||126.96.36.199, 188.8.131.52, 184.108.40.206||220.127.116.11/29, 18.104.22.168/29, 22.214.171.124/29|
|East US 2||126.96.36.199, 188.8.131.52, 184.108.40.206, 220.127.116.11, 18.104.22.168||22.214.171.124/29, 126.96.36.199/29, 188.8.131.52/29|
|France Central||184.108.40.206, 220.127.116.11, 18.104.22.168||22.214.171.124/29, 126.96.36.199/29|
|France South||188.8.131.52, 184.108.40.206 ,220.127.116.11||18.104.22.168/29, 22.214.171.124/29|
|Germany West Central||126.96.36.199, 188.8.131.52, 184.108.40.206||220.127.116.11/29, 18.104.22.168/29, 22.214.171.124/29|
|Central India||126.96.36.199, 188.8.131.52 , 184.108.40.206, 220.127.116.11, 18.104.22.168||22.214.171.124/29, 126.96.36.199/29|
|South India||188.8.131.52||184.108.40.206/29, 220.127.116.11/29|
|West India||18.104.22.168, 22.214.171.124||126.96.36.199/29, 188.8.131.52/29|
|Japan East||184.108.40.206, 220.127.116.11, 18.104.22.168, 22.214.171.124||126.96.36.199/29, 188.8.131.52/29, 184.108.40.206/29|
|Japan West||220.127.116.11, 18.104.22.168||22.214.171.124/29|
|Korea Central||126.96.36.199, 188.8.131.52 ,184.108.40.206, 220.127.116.11, 18.104.22.168||22.214.171.124/29,126.96.36.199/29, 188.8.131.52/29|
|North Central US||184.108.40.206, 220.127.116.11||18.104.22.168/29|
|North Europe||22.214.171.124, 126.96.36.199||188.8.131.52/29, 184.108.40.206/29, 220.127.116.11/29|
|Norway East||18.104.22.168, 22.214.171.124, 126.96.36.199, 188.8.131.52||184.108.40.206/29|
|South Africa North||220.127.116.11, 18.104.22.168, 22.214.171.124||126.96.36.199/29, 188.8.131.52/29, 184.108.40.206/29|
|South Africa West||220.127.116.11||18.104.22.168/29|
|South Central US||22.214.171.124, 126.96.36.199, 188.8.131.52||184.108.40.206/29, 220.127.116.11/29, 18.104.22.168/29, 22.214.171.124/29|
|South East Asia||126.96.36.199, 188.8.131.52, 184.108.40.206||220.127.116.11/29, 18.104.22.168/29, 22.214.171.124/29|
|Switzerland North||126.96.36.199||188.8.131.52/29, 184.108.40.206/29, 220.127.116.11/29, 18.104.22.168/27|
|UAE Central||22.214.171.124||126.96.36.199/29, 188.8.131.52/29|
|UAE North||184.108.40.206||220.127.116.11/29, 18.104.22.168/29|
|UK South||22.214.171.124, 126.96.36.199, 188.8.131.52, 184.108.40.206||220.127.116.11/29, 18.104.22.168/29, 22.214.171.124/29|
|UK West||126.96.36.199, 188.8.131.52, 184.108.40.206||220.127.116.11/29, 18.104.22.168/29|
|West Central US||22.214.171.124, 126.96.36.199, 188.8.131.52, 184.108.40.206||220.127.116.11/29|
|West Europe||18.104.22.168, 22.214.171.124||126.96.36.199/29, 188.8.131.52/29, 184.108.40.206/29|
|West US||220.127.116.11, 18.104.22.168||22.214.171.124/29|
|West US 2||126.96.36.199, 188.8.131.52||184.108.40.206/29, 220.127.116.11/29, 18.104.22.168/29|
|West US 3||22.214.171.124, 126.96.36.199||188.8.131.52/29, 184.108.40.206/29, 220.127.116.11/29|
- For information on how to change the Azure SQL Database connection policy for a server, see conn-policy.
- For information about Azure SQL Database connection behavior for clients that use ADO.NET 4.5 or a later version, see Ports beyond 1433 for ADO.NET 4.5.
- For general application development overview information, see SQL Database Application Development Overview.
- Refer to Azure IP Ranges and Service Tags – Public Cloud
- What is a logical SQL server in Azure SQL Database and Azure Synapse?
- What's the difference between Azure Synapse (formerly SQL DW) and Azure Synapse Analytics Workspace
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