SQL Connection Error

Question

Hey guys I need a little help. I am getting the following error opening a sql connection. I cannot figure out what is going on. I am running a packet capture on the system I have vs installed on, on the firewall, and on the target sql server, and none of the packets are being sent. Its over a VPN but I have done this before with no issue. I have tried by IP and hostname. I cannot figure out where the packets are being sent

 

In this string I have tried using \\ and not using \\ in front of the host name. I have tried like I said hostname and IP. 

 

string connectionString = "Data Source=\\10.3.3.45\\SQLEXPRESS;Initial Catalog=wirelessdevices;User ID=wireless;Password=test";

 

 

"{"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 25 - Connection string is not valid)"}"