Error:

A transport-level error has occurred when sending the request to the server. (Provider: Session Provider, error: 19 – Physical connection is not usable)

Snapshot:

Causes:

Server side:

Make sure that you have enabled remote connections on the instance RELYONDB

Make sure that firewall is OFF.

Create an exception for SqlBrowser.exe and SqlServer.exe in server computer.

Client side:

Make sure that you have typed correct server computer name and instance name

Make sure that server machine is reachable. Check you are able to ping the server.

Make sure that you are able to access the shared folder of remote server.

Make sure that you are able to connect SQL Server using the Telnet command.

Enter correct system name and instance name.

VIA protocol might be enabled and it may be using port 1433.

Workaround 1:

Enable Using both TCP/IP and Named Pipes:

All programs | Microsoft SQL Server 2005| Configuration Tools | SQL Server Surface Area Configuration | Configuration for Services and Connections | Remote Connections, choose Local and Remote Connections |Enable Using both TCP/IP and Named Pipes.

Restart SQL Server RELYONDB & SQL Server Browser service.

Workaround2:

Enable Using both TCP/IP and Named Pipes:

All programs | Microsoft SQL Server 2005| Configuration Tools | SQL Server Configuration Manager| SQL Server Network configuration| Right Click “Named Pipes” & Click Enable > Right Click “TCP\IP” & Click Enable

Restart SQL Server RELYONDB and SQL Server Browser service.

Workaround 3: 

Click Start | Run | type firewall.cpl | Switch Off | Click OK.

Workaround 4:

Disable “VIA” protocol:

Open SQL Server Configuration Manager as Run as Administrator

All programs | Microsoft SQL Server 2005| Configuration Tools | SQL Server Configuration Manager | SQL Server Network configuration | Protocols for RELYONDB

The status of “VIA” protocol should be disabled |

Right click “VIA” | Properties | Default Port should be empty.