Using Transparent Network IP Resolution

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW)

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Purpose

Transparent Network IP Resolution (TNIR) is a revision of the existing MultiSubnetFailover feature. TNIR affects the connection sequence of the driver in the case where the first resolved IP of the hostname does not respond and there are multiple IPs associated with the hostname. TNIR interacts with MultiSubnetFailover to provide the following three connection sequences:

• 0: One IP is attempted, followed by all IPs in parallel
• 1: All IPs are attempted in parallel
• 2: All IPs are attempted one after another

TransparentNetworkIPResolution	MultiSubnetFailover	Behavior
True	True	1
True	False	0
False	True	1
False	False	2

Setting Transparent Network IP Resolution

TransparentNetworkIPResolution is enabled by default. MultiSubnetFailover is disabled by default. The following pages provide more information about setting these properties:

• Using Connection String Keywords with OLE DB Driver for SQL Server
• Initialization and Authorization Properties

See Also

OLE DB Driver for SQL Server Support for High Availability, Disaster Recovery