> # Planning SequeLink® Server Data Sources

> Server data sources define the characteristics of the connection between the SequeLink Client and the database. A server data source, although it resides on the server, also contains settings that are relevant to the SequeLink Client. When you centralize data source information on the server, SequeLink can provide "near-zero" client administration.

> When you install the SequeLink Server, a default server data source, named Default, is automatically created and configured. See "Planning SequeLink® Data Access Services" for information about the default behavior of this data source.

> If the default server data source definition does not meet your needs, you can modify the default data source, or you can create a new server data source, and specify it when you configure the client data source.

> ### Configuring a Connection to a SequeLink® Server

> SequeLink allows you to configure a connection from the SequeLink Client to a SequeLink Server in either of the following ways:

> - Specify the connection information directly in the SequeLink ODBC, ADO, .NET, or JDBC Client data source. This information includes the TCP/IP address (or host name), the port number of the SequeLink Server, and, optionally, a SequeLink Server data source to use.

> - Specify a Distinguished Name (DN) identifying a specific entry in an LDAP directory. The LDAP directory entry contains the information needed to connect to the SequeLink Server. Using this method, the ODBC, ADO, or JDBC Client retrieves the connection information from the LDAP directory.

> The advantage of using LDAP is that you can centrally store connection information, which provides the flexibility to make environment changes. For example, if you move the database and SequeLink Server to a different server, you do not have to reconfigure your user applications or multiple SequeLink Client data sources that access the SequeLink Server; the connection information is specified in an LDAP directory, not in the SequeLink Client data source. Therefore, you need only make a single change in the LDAP directory entries.

> For JDBC Clients, JDBC data sources store connection instructions in a JNDI infrastructure, which can support LDAP.

> ### Referencing a Server Data Source

> If you do not specify a server data source when configuring a client data source, the client data source uses the default server data source. "General Data Source Default Behavior" describes the behavior of the default server data source. If the default server data source definition does not meet your needs, you can modify the default server data source, or you can create a new server data source and then specify the new server data source when configuring your client data source.