I need to test the connectivity of SQL Server with my remote machine,
I have SQL server name not IP address.
How can I check this connectivity.
How will I know on which port the communication enabled.
You need to try to connect, there is no way find on which port someone is listening without directly asking, hey, is there anyone on this port?
Here is the way to do so from C#:
TcpClient tc = null;
try
{
tc = new TcpClient("MyAddress", MyPort);
// port is open
}
catch(SocketException se)
{
// port is not open, or host is not reachable
}
finally
{
tc.Close();
}
Well you must know on which port the Sql server services are listening on remote server. Default port is 1433.
If you want to test if a port is open on a server or not then you can try Telnet ping.
open command prompt:
C:\> Telnet <YourServername> <portno.>
If it's open then a screen will go empty immediately or return an error.
You need to know the IP address or host name of the server and the TCP port, too. The instance name alone won't help, as they are not advertised on the network. If you have the server's name or IP and the SQL Server instance name, you can simply try to connect using an SqlConnection with an appropriate connection string. If you can connect, everything's fine.
Related
I have a server and a client app, the server throws no exception and seems to listen properly but the clients aren't able to connect for some reasons, I tried with both local network and public IP.
-With local network's IP I can connect to it only when the client app is runned on the same computer than the server.
-With public IP nothing can connect to the server.
However in both cases when the connection fails, it behaves always the same : waits for aproximately 5-10 seconds and then throws System.Net.Socket.SocketException. I tried with port 1507 first then tried with port 80 but it didn't change anything
Server
IPAddress adress = IPAddress.Parse(MyIp);
TcpListener listener = new TcpListener(adress, 80);
listener.Start();
TcpClient Client = await listener.AcceptTcpClientAsync();
Client
TcpClient client = new TcpClient();
client.ConnectAsync(IPAddress.Parse(MyIp), 80).GetAwaiter().GetResult();
I don't understand where the problem comes from, is it coming from my code or not? If not the what could it be and how could I fix it?
Have you tried Telnet from outside network on specific port?
If you can't connect probably is router port redirection or access is blocked by firewall.
[edit] so not sure what happened, but we ended up resetting the server and turning off/on TCP/IP and Named Pipes and after a restart and updating the settings everything started working again. weirdest thing. anyways thanks for the help guys.
I'm building a C# WPF application for my job, and I'm getting a weird problem that I've been trying to figure out for the past week. The application connects to the server and imports several tables on start up. So I built it out and was testing it with no issues, but when i pass it to our testers, and everyone is getting the following errors:
Provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server
The users are able to connect to the server through other methods (SSMS/Excel VBA), but just through the application it won't work.
I've checked the following:
Remote connections enabled
TCP/IP connections enabled
Firewall settings are the exact same across all users (me included)
application is compiled as 32 bit (saw this in another thread)
We're using SQL Server 2008 and I've tried several connection strings/methods.
below is the code I'm using to connect:
public void Open_DB_Conn(string Connection_Str)
{
try
{
Sql_Conn = new SqlConnection(Conn_Str);
Sql_Conn.Open();
}
catch (Exception e)
{
MessageBox.Show(string.Format("Error Message:{0} Conn String: {1}",e.Message,Conn_Str));
}
}
Below is my connection string (this is just one of many iterations I've used trying to get it working):
Data Source=IP Address;Initial Catalog=DB_Name;User ID=LOGIN;Password=PWD
Anyone know why I would be the only one able to get it to work and that the users are able to login to the server using other applications without a problem? They use it for logging their excel VBA scripts and there aren't any issues there.
Try this - it may be your answer
"The error is reported by client library. While your server is listeing on remote TCP, client will still try TCP and NP connection in order. So the error client behavior is expected. From what you have described, I believe that even though you enabled the remote TCP connection on the XPSP2 machine, you didn't make the TCP listening port an exception of XPSP2 personal firewall. You should follow steps below to resolve this issue.
check the SQL Server Errorlog to make sure SQL Server is now listening on TCP/IP and confirm which port it is listening on. Usually 1433. In the Errorlog, you will see several lines that discuss what SQL Server is listening on. Below is an example:
2006-01-04 01:41:07.65 server SQL server listening on 10.254.1.150: 1433. <--Shows the IP Address and the port.
2006-01-04 01:41:07.65 server SQL server listening on 127.0.0.1: 1433. <--Shows another IP Address and the port.
2006-01-04 01:41:07.69 server SQL server listening on TCP, Shared Memory, Named Pipes.
2006-01-04 01:41:07.69 server SQL Server is ready for client connections
2, Make sure on Windows XP that the firewall is not blocking that port.
3, go to your client machine and run the client network configuration tool (cliconfg.exe) Make sure TCP/IP is enabled, click properties and make sure the port number is the same one as SQL Server is listening on. Here you can enable NP or disable client NP as well.
Once both the client and the server are using TCP/IP with the same port number and the firewall on server machines is not blocked, you should be able to connect.
Hope this helps."
(Ref: http://social.technet.microsoft.com/Forums/sqlserver/en-US/c488cf76-2515-440f-b3f8-9cfad689c5b6/named-pipes-provider-error-40-could-not-open-a-connection-to-sql-server?forum=sqldataaccess)
You have to configured your SQl server so that other IP can connect it for that you have to gone through mentioned link
Configure SQL server
What authentication are you using for the SQL Server? Windows Authentication or SQL Server authentication? My suggestion is to first turn on SQL Server authentication and use the sa\password to connect to the server. If you are successful, then ask the others (users of your application) to try with the same connection string. Let me know what you find out.
Be sure that the port specified in:
Data Source="IPAddress,port";Initial Catalog=DB_Name;User ID=LOGIN;Password=PWD
matches the port on your SQL Server. You can check that by going on SQL Server COnfiguration Manager and viewing TCP/IP properties.
EDIT :
It is also the case the port defined by blocked by an external firewall. And the rest Applications use other ports. Try to find out which port you can use (if indeed the are restrictions to your network)
Make sure your SQL Server instance is properly configured to use TCP using Sql Server Configuration Manager.
It is by default disabled in SQL Express, as show below.
I'd like to know more about your "Sql_Conn" class.
Also, try using this for your connection.
using (var conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString))
{
conn.Open();
using (var cmd = conn.CreateCommand())
{
string cmdText = "SELECT name FROM sys.tables"
cmd.CommandText = cmdText;
cmd.ExecuteNonQuery();
}
}
I'm currently working with TCP/IP Sockets, My client console program has to connect with server which is my PC, If the destination in the client program is specified as a local host it works fine, what I need to get done with is to connecting the client with my server through internet, what I did is looked up for my IP address on http://www.whatismyip.com/ and tried but it didn't work as I think it's a Network Interface IP address, then I altered destination IP address in client program specifically to the address of my computer which I want it to be a server, but that didn't work also. Here's my code.
Ip = (IPAddress.Parse("192.168.1.4"));
MyClient.Connect(Ip,6000);
GetStream = MyClient.GetStream();
Console.WriteLine("CONNECTED TO SERVER");
Read = new BinaryReader(GetStream);
Write = new BinaryWriter(GetStream);
There 2 things (at least) that you should be aware of:
1. To access your computer from Internet (from the public address, the one you get with whatismyip.com) you need to open the port (6000) at the router, and tell the router to what IP it should forward the incoming connection. You could specified specifics ports or put a DMZ host where all the incoming connections will be routed to that host/PC. Read your router manual to see how that is done.
2. You cannot access your public IP from the inner side of the router (intranet), if you want to connect to your public IP you need to be in another network.
If you have a dynamic IP (is the default) every time the router is powered off and on then, most probably, that IP would change, you need to investigate thru whatismyip.com in order to know what IP has been assigned. You could connect to dyndns.org and ask for a host name myhost.mydomain.com (.es, .fr, etc), and in the router tell the DDNS (Dynamic DNS) to update that host every time the IP changes. In your client program you then connect to MyClient.Connect("myhost.mydomain.com", 6000);
Hope I explain myself well enough, anyway, if you have any question let me know.
I just want to know the right sql connection string for a remote sql server express edition.
This is what I got but I got some problems
SqlConnection cs = new SqlConnection(#"Data Source=(IP Address)\PC-NAME\SQLEXPRESS,1433;Network Library=DBMSSOCN;Initial Catalog=dbase;User ID=sa;Password=password");
I got this error in my C# debugger:
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: TCP Provider, error: 0 - A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)
Thanks in advance!
From your comment:
The IP address is the static IP address. I am trying to connect outside the building.
If the database you are trying to connect to is on a computer behind a [router/firewall/modem] that has the target address, you will need to use port forwarding on the [router/firewall/modem] to forward all connections on TCP port 1433 through to the target machine.
If you are trying to connect to a home computer behind an ADSL modem with a static IP address, your ADSL modem needs to be configured with port forwarding to connect the external port 1433 with the same port on the internal address. This must be done on the modem, and cannot be done just with a connection string.
Let's say you have an ADSL modem listening on 127.2.3.4 (invalid address for demonstration only) and a PC behind that with an IP address of 192.168.0.100. Configure the modem to forward port 1433 to 192.168.0.100:1433 (how will depend on make and model of modem). Then your connection string would be:
Data Source=127.2.3.4\SQLEXPRESS,1433;Network Library=DBMSSOCN;Initial Catalog=dbase;User ID=sa;Password=password
Assuming that SQLEXPRESS is the only database instance on the server, and since port 1433 is the default, you could use the simpler:
Data Source=tcp:127.2.3.4;Initial Catalog=dbase;User ID=sa;Password=password
The Network Library=DBMSSOCN specification is replaced with tcp: and defaults are assumed for instance and port.
Solution : if you are providing remote machine IP address then you don't need to provide hostname
Try This:
SqlConnection cs = new SqlConnection(#"Data Source=(IP Address)\SQLEXPRESS,1433;Network Library=DBMSSOCN;Initial Catalog=dbase;User ID=sa;Password=password");
Why don't you try SqlConnection String Builder here.
I'm working on a simple hello world TCP/IP client server app in C# and am unable to get my client to connect. Can anyone offer any additional troubleshooting steps? I'm starting to run out of ideas...
Here are the relevant sections of code:
server:
Console.Out.WriteLine("About to bind address");
IPAddress ipAd = IPAddress.Parse("127.0.0.1");
Console.Out.WriteLine("Choose a port to bind...");
String port = Console.In.ReadLine();
int iPort = Int32.Parse(port);
TcpListener myList = new TcpListener(ipAd, iPort);
myList.Start();
Console.WriteLine("The server is running at: "+myList.LocalEndpoint);
Console.WriteLine("Waiting for a connection.....");
Socket s = myList.AcceptSocket();
Console.WriteLine("Connection accepted from " + s.RemoteEndPoint);
client:
Console.Out.WriteLine("enter address: ");
string address = Console.In.ReadLine();
Console.Out.WriteLine("enter port: ");
int port = Convert.ToInt32(Console.In.ReadLine());
TcpClient tcpclnt = new TcpClient();
Console.WriteLine("Connecting.....");
Console.Out.WriteLine("Address: " + address + ":" + port);
tcpclnt.Connect(address, port);
I am able to ping the server from the client machine, however I am unable to telnet to the server using the bound port. I've tried a variety of ports (a few in the low 8000s and a few up around 40000). I have disable windows firewall on both systems. The systems are connected to a router which is not on the internet. I've tried with and without port forwarding set to forward incoming requests on the given port to the server machine with no effect.
The only exception that I've been able to trap is thrown by the client:
No connection could be made because
the target machine actively refuses
it.
I checked for an InnerException but it seems that there are none - that is the base exception. Could that be right?
Not sure what else I should be looking at - any additional troubleshooting steps would be helpful.
Thanks!
I've run into this before. The trick is to bind to 0.0.0.0 rather than 127.0.0.1. When you bind to 127.0.0.1 the server will only accept connections from localhost. Binding to 0.0.0.0 it will accept all requests.
You also may want to nmap the host machine from the client and see what ports it sees as being open.
EDIT: If you hard code the IP address of the machine in it the listener will only listen on that network interface. If you use 0.0.0.0 the listener will listen on all available network interfaces. This includes interfaces between your computer and a USB attached hand held device, a second network card or a VPN link.
The code above is listening to request coming from the loopback address. This will effectively only listen to connection on that network, and that network only includes your machine.
Have you tried listening to the address bound to the network from which the connection should be coming? On a local network it should be something like 192.168.x.x or 10.x.x.x
try netstat -al on your machine (the exact command line varies between Windows and unix) and see if the server is listening on the port
Why don't you use .NET remoting? It is better than doing a TCP/IP client server. You can pass messages between objects.
Have you tried running the client server on the same machine to make sure the connection is made first? Beyond that try using the router assigned or static IP of the machine running the server vs binding to loopback.