Permanent error 11001

SQL server error 11001 occurs when the SQL Server can’t be found on Network.

This happens if the IP address is not reachable or the TCP port number is either not open or is not the correct port number or is blocked by a firewall

Here at Bobcares, we have seen several such SQL related issues as part of our Server Management Services for web hosts and online service providers.

Today we’ll take a look at the cause for this error and how to fix it.

Why does SQL server error 11001 occur

Now let’s look into what causes this error to occur

1. This error mainly occurs when the SQL Server client can’t connect to the server. This may happen when the client cannot resolve the name of the server or the name of the server is incorrect.

2. If we want to access a SQL server beyond a local area network then the connection must pass through one or more routers and at least one Proxy/Firewall. Sometimes, the Firewall and/or Proxy may not allow SQL Server to be accessed from an external location.

For instance, the error appears as below.

How we resolve SQL server error 11001

Here are the steps that our Support Engineers provide to our customers to follow to fix this error.

1. Enter the correct server name on the client such that you can resolve the name of the server from the client. Also, to check the TCP/IP name resolution, we suggest using the ping command in the Windows operating system.

Also, make sure you are using the correct instance name. When connecting to a default instance, machinename is the best representative for the instance name and when connecting to a named instance such as sqlexpress, we suggest specifying the instancename as follows: machinenameinstancename.

Here, enter the SQL Server instance name for instancename.

Also, check that the SQL Server is in the network. Use the command SQLCMD -L to retrieve the list of SQL Servers installed in the network.

NOTE: This will only return SQL Servers if the SQL Server Browser service is running.

2. We suggest running netsvrcn.exe using command prompt as an Administrator on the ‘Server’ running the MSDE Database.

3. Enable TCP/IP and Named Pipes protocol

Check the TCP/IP and Named Pipes protocols and port. First, open SQL Server Configuration Manager and check the SQL Server Network Configuration protocols. Named Pipes and TCP/IP protocol must be enabled.

For the TCP/IP protocol, right-click and select properties and then check the TCP/IP communication port. The default port is 1433. However, this can be changed for security purposes if needed.

4. Restart the SQL Server instance.

5. From the firewall using ‘Windows Firewall Advanced Security’, exclude the ports SQL Server normally listens on, for both inbound and outbound rules:

1433 TCP port
1434 UDP port

6. SQL Server Browser service must be running. You can check the browser service status using either SQL Server Configuration Manager or the SC command as follows.

sc query sqlbrowser

[Need any further assistance in fixing SQL errors? – We’re available 24*7]

Conclusion

In short, this error occurs when the SQL Server can’t be found on Network. Today, we saw the resolution to this SQL error.

var google_conversion_label = «owonCMyG5nEQ0aD71QM»;

Symptoms

• Remote computer status is shown as «Offline» in the Viewer address book.
• You can establish a remote connection, but the connection is unstable.

When you examine the Host log (or Agent log, if Agent is used) you see the following error: Socket Error # 11001 Host not found.(EIdSocketError)

Cause

This error means that the remote Host or Agent is unavailable due to one of these reasons:

• DNS problem, i.e. the IP address of the intermediate server cannot be resolved from its DNS name.
• The intermediate server address or outbound port are blocked by the firewall.

Solution 1: Clear the DNS cache

1. Press Win+R to open the Run dialog.
2. Type ipconfig /flushdns and click OK (or press Enter) to clear the DNS cache:
   
3. Right click on the Host icon in the tray area and select Restart Host. Wait 10-20 seconds until the Host restarts and connects back to the intermediate server.

Solution 2: Check connectivity with our public server

If you use our public Internet-ID service make sure that the primary server at id.remoteutilities.com can be accessed from the Host PC and the IP address of the server can be resolved successfully.

1. Press Win+R to open the Run dialog.
2. Type cmd and click OK (or press Enter). The Command Prompt will open.
3. Type ping id.remoteutilities.com and press Enter.
4. If the ping command and DNS resolution are successful, the result will be shown in the CMD window:
   
5. If you receive «Request timed out» as a response, the ID server cannot be reached from the Host location. Please, contact your system administrator.

Solution 3: Make sure outbound connection is allowed

The Internet-ID connection requires some outbound ports to be open. When used with our public service the ports used are TCP 5655 and 443. Make sure that the Host can establish outbound connections on these ports or allow the ports in the local and perimeter firewall if necessary.

Even if outbound connections on TCP ports 5655 and 443 are allowed on the Host machine and in the perimeter firewall, such connections may still be blocked on the ISP level. In this case you should contact your ISP representative.