How To Use ADO to Connect to a SQL Server That Is Behind a Firewall

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Article ID: 269882 - View products that this article applies to.
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When you use ActiveX Data Objects (ADO) to connect to a SQL Server 7.0 or SQL Server 2000 server that is behind a firewall, consider the following:
  • The firewall must be configured to permit port 1433 incoming (or the port numbers that SQL Server listens to on TCP/IP), and ports 1024 to 65535 outgoing.
  • The connection string must specify the SQL Server address: the IP address, the server DNS name, or a name inside the hosts file.
  • The connection string should specify the Network Library type, in this case "dbmssocn" (without the quotes) for TCP/IP Sockets Net-Library.
WARNING: Opening up the ports on the firewall may pose security issues; consult with your System Administrator or Security Administrator to configure the firewall.


In the following sample code, servername should be the server DNS name, IP address, or a name inside the hosts file:
Set Conn = CreateObject("ADODB.Connection")
Set Rs = CreateObject("ADODB.Recordset")
Set Cmd = Createobject("ADODB.Command")
Conn.Open "Provider=SQLOLEDB;Password=password;Persist Security Info=True;User ID=username;Initial Catalog=DBNAME;Data Source=servername;Network Library=dbmssocn"

SQL = "Select * from TABLE"

Cmd.CommandText = SQL
Set Rs = Cmd.Execute


For additional information, click the article number below to view the article in the Microsoft Knowledge Base:
238949 How To Set the SQL Server Network Library in an ADO Connection String


Article ID: 269882 - Last Review: July 15, 2004 - Revision: 4.5
  • Microsoft ActiveX Data Objects 1.0
  • Microsoft ActiveX Data Objects 1.5
  • Microsoft ActiveX Data Objects 2.0
  • Microsoft ActiveX Data Objects 2.01
  • Microsoft ActiveX Data Objects 2.1
  • Microsoft ActiveX Data Objects 2.1 Service Pack 1
  • Microsoft ActiveX Data Objects 2.1 Service Pack 2
  • Microsoft ActiveX Data Objects 2.5
  • Microsoft ActiveX Data Objects 2.6
  • Microsoft SQL Server 7.0 Standard Edition
  • Microsoft SQL Server 2000 Standard Edition
kbhowto KB269882

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