Not connecting to SQL Server over VPN

问题:

I have connected for the first time to an existing network over VPN. I can ping the IP address which is used by the SQL Server from the VPN client, but SSMS does not connect to the SQL Server. I am using the right login id and password.

Why could this happen ? Any ideas ?

Thanks

回答1:

On a default instance, SQL Server listens on TCP/1433 by default. This can be changed. On a named instance, unless configured differently, SQL Server listens on a dynamic TCP port. What that means is should SQL Server discover that the port is in use, it will pick another TCP port. How clients usually find the right port in the case of a named instance is by talking to the SQL Server Listener Service/SQL Browser. That listens on UDP/1434 and cannot be changed. If you have a named instance, you can configure a static port and if you have a need to use Kerberos authentication/delegation, you should.

What you'll need to determine is what port your SQL Server is listening on. Then you'll need to get with your networking/security folks to determine if they allow communication to that port via VPN. If they are, as indicated, check your firewall settings. Some systems have multiple firewalls (my laptop is an example). If so, you'll need to check all the firewalls on your system.

If all of those are correct, verify the server doesn't have an IPSEC policy that restricts access to the SQL Server port via IP address. That also could result in you being blocked.

回答2:

When this happens to me, it is because DNS is not working properly. Try using the IP address instead of the server name in the SQL Server login.

回答3:

Make sure SQL Server is enabled for TCP/IP (someone may have disabled it)?

This will also help you to check/verify the port number the SQL instance is using (in case someone changed it from the default of port 1433).

Obviously port 1433 (or whatever port SQL is listening on) needs to be unblocked by any firewalls between your machine and the box SQL is running on.

To check SQL's network configuration (requires SQL Server Client Tools installed): Start -> Programs -> SQL Server 200x -> Configuration Tools -> SQL Server Configuration Manager

Connect to the machine you need then expand the Tree Item (LHS) "SQL Server Network Configuration", then pick instance. You should have four options - Shared Memory, Named Pipes, TCP/IP and VIA. You can check that TCP/IP is enabled in the RHS window.

If you double click TCP/IP and hit the "Advanced" tab, you can also view the Port number.

Other thoughts.. Are you using SQL Authentication or Windows (Domain) authentication?

• If SQL Authentication (which I assume you are using given you said username and password), are you sure the SQL instance you're connecting to has mixed mode authentication enabled? If not, you have to connect as Administrator and change the default security settings to allow SQL authentication.

• If Windows Authentication, could your network be using Kerberos potentially? One would think the VPN credentials would be used for the handshake. I'd check your account has appropriate login rights.

回答4:

Check that the port that SQL Server is using is not being blocked by either your firewall or the VPN.

回答5:

I also had this problem when trying to connect remotely via the Hamachi VPN. I had tried everything available on the internet (including this post) and it still did not work. Note that everything worked fine when the same database was installed on a machine on my local network. Finally I was able to achieve success using the following fix: on the remote machine, enable the IP address on the TCP/IP protocol, like so:

On the remote machine, start SQL Server Configuration Manager, expand SQL Server Network Configuration, select "Protocols for SQLEXPRESS" (or "MSSQLSERVER"), right-click on TCP/IP, on the resulting dialog box go to the IP Addresses tab, and make sure the "IP1" element is Active=Yes and Enabled=Yes. Make note of the IP address (for me it wasn't necessary to modify these). Then stop and start the SQL Server Services. After that, ensure that the firewall on the remote machine is either disabled, or an exception is allowed for port 1433 that includes both the local subnet and the subnet for the address noted in the previous dialog box. On your local machine you should be able to connect by setting the server name to 192.168.1.22\SQLEXPRESS (or [ip address of remote machine]\[SQL server instance name]).

Hope that helps.

回答6:

You may not have the UDP port open/VPN-forwarded, it's port number 1433.

Despite client protocol name of "TCP/IP", mssql uses UDP for bitbanging.

回答7:

SQL Server uses the TCP port 1433. This is probably blocked either by the VPN tunnel or by a firewall on the server.

回答8:

When connecting to VPN every message goes through VPN server and it could not be forwarding your messages to that port SQL server is working on.

Try

disable VPN settings->Properties->TCP/IP properties->Advanced->Use default gateway on remote network.

This way you will first try to connect local IP of SQL server and only then use VPN server to forward you

回答9:

I have this issue a lot with Citrix Access Gateway. I usually get a timeout error. If you are able to connect to the database from a client on the network, but not from a remote client via VPN, you can forget most suggestions given here, because they all address server-side issues.

I am able to connect when I increase the timeout from the default (15 seconds) to 60 seconds, and for good measure, force the protocol to TCP/IP. These things can be done on the Options screen of the login dialog:

回答10:

This is what fixed my connection problem of accessing the SQL Server 2012 Database via VPN

With the SQL Server 2012 Configuration Manager,

I went to the SQL Server Network configuration

Then clicked on the NEW server instance and double-clicked the TCP/IP protocol [I had also previously enabled this option and rebooted the server but that did still not fix it]

now that the TCP/IP was enabled, I noted that all of the IP port slots in the 'IP Addresses' tab of the TCP/IP Properties advanced dialog were set to Enabled=No.

I was curious to why my new installation set all of these IP slots to NO rather than Yes, so I just changed them to YES.

Now the connection to the sever via VPN works great, I did not change any port numbers.

Note: I also had SQL Server 2008 default from the Visual studio 2010 uninstalled, but I do not think that had a direct effect to the TCP/IP situation. A coworker told me that the the 2008 and 2005 installations which come with visual studio may interfere with SQL 2012.

回答11:

As long as you have the firewall set to allow the port that your SQL Server instance is using, all you need to do is change Data Source from =Server name to =IP,Port

ie, in the connection string use something like this.

Data Source=190.190.1.100,1433;

You should not have to change anything on the client side.

回答12:

I was having this issue too with SQL Server 2017.

I'm on the same network as the server via VPN and can ping it. After being frustrated that no authentication method would work - I set up an SSH server on the SQL server - and I was able to connect normally. This confirmed the correct port wasn't being hit for some reason. I even created a new user accounts, domain accounts, firewall checks on both ends, etc...

The solution for me was: 1. Set Connection to strictly use TCP/IP on SSMS 2. Use a custom string to point to the default port (ex: Data Source=192.168.168.166,1433;)

All the other comments above haven't worked so far. It looks like it was mandatory to include the port (even though its default).

回答13:

if you're using sql server 2005, start sql server browser service first