Using Visual Studio, You can find Web.config file in Your Application Treeview from Solution Explorer Window. Edit the underlined part to Your new IP addredd
<add name="XXXXX" connectionstring="Data Source=<u><b>10.1.1.1</b></u>; user id=XXXX;> <br mode=" hold=" /><br mode="></add>
Open the web.config file for the Web service that you want to modify.
The web.config file is found in the virtual folder for the Web service, such as C:\Inetpub\wwwroot\LoggingService.
Locate the <connectionStrings> element.
In the <add> element, set the connectionString attribute to the new connection string.
For example, to change the server name, in the connectionString attribute, change the value of the Data Source string