Hey there, let’s work through this connection problem together. I’ve dealt with similar compatibility headaches between older SQL Native Clients and newer SQL Server versions, so here’s a structured set of fixes to try:

1. Verify SQL Server Protocol Configurations #

• Open SQL Server Configuration Manager (for your 2014 instance) and confirm both Shared Memory and TCP/IP protocols are enabled under "SQL Server Network Configuration > Protocols for [Instance Name]".
• For TCP/IP: Double-click it, go to the "IP Addresses" tab, ensure the correct port (default 1433 or your custom port) is listed under "TCP Port" for your server’s IP, and that "Listen All" is set to Yes.
• Restart the SQL Server service to apply any protocol changes—this is easy to forget but critical.

2. Update SQL Server Native Client 10.0 to the Latest Patch #

The base version of SQL Server Native Client 10.0 (shipped with SQL Server 2008) has limited support for SQL Server 2014. Install the SQL Server 2008 SP4 update (the final service pack for 2008) to patch the client with improved compatibility for newer SQL Server versions. This fixes a lot of pipe/TCP connection bugs related to protocol mismatches.

3. Adjust Connection String Parameters #

Even though your SSIS packages are 2008-built, tweak the connection string to force settings that play nicer with 2014:

• For TCP connections, explicitly specify the port to avoid resolution issues:

  Data Source=YourServerName,1433;Network Library=DBMSSOCN;Initial Catalog=YourDB;User ID=YourUser;Password=YourPass;
  

• Try disabling encryption temporarily to rule out compatibility issues with 2014’s default encryption settings:

  Encrypt=No;TrustServerCertificate=Yes;
  

4. Check SQL Server Authentication & Permissions #

• Ensure your SQL Server 2014 instance is set to Mixed Mode Authentication (if you’re using a SQL login instead of Windows auth). You can adjust this in SSMS: Right-click the server > Properties > Security.
• Verify the login account you’re using has CONNECT SQL permission on the 2014 instance, and can access the target database. Test the login directly in SSMS first to rule out permission-related blocks.

5. Rule Out Network & Firewall Blocks #

• Use PowerShell to test TCP connectivity to the server port:

  Test-NetConnection YourServerName -Port 1433
  

• Check both local machine firewall and server-side firewall to ensure the SQL Server port (1433 or custom) is allowed inbound/outbound. Also, temporarily disable any antivirus software on the client or server to see if it’s blocking the connection.

Bonus: Consider SSIS Package Upgrade (If Permitted) #

If your project allows it, upgrading the SSIS packages from 2008 to 2014 format would let you use SQL Server Native Client 11.0 natively, which is fully compatible with SQL Server 2014. This is a longer-term fix but avoids ongoing compatibility issues with older clients.

内容的提问来源于stack exchange，提问作者Rhys