[Windows, SQL Server] How to verify SQL Server port is opened from the client computer?

How to verify the SQL Server port is opened from the client computer?

Situation

You want to make sure that the SQL Server service port is opened and can connect from the client computer.

If you want to verify the listening port on SQL Server, take a look here.

Telnet Client

The telnet command is a very traditional old way to check the server port is opened.

Moreover, it's also possible to use the same command parameters as Linux.

But, you have to turn on Windows feature as below. 

And may require your computer reboot.

telnet <desination host> <destination port>

You may wait until it returns the result when it fails or you have to close the window even if it succeeded.

Luckily, there are 2 more ways you can do that quite easily.

PsPing

PsPing is one of the utility applications from PsTools.

You can download PsTools from here.

It enables you to check the qualities of "ICMP, TCP and UDP" connections.

Basic command

psping <Destination host>:<Destination port>

It has lots of options/parameters you can use. For example, you want to use PsPing with

• 2 seconds interval,
• 10 times try,
• Use IPv4,
• The destination host is "testserver",
• The destination port is "1433" 

then, the command would be like this.

 

Note! You need to perform this operation on the same directory whereas the executable files located. You can add the directory to your Path(System Properties > Advanced > Environment Variables > Path > Add directory of the file location)  Alternatively, you can copy the executable files to the current system directory e.g. C:\Windows\System32.

Portping

PortPing is the simplest tool to check the port (from my perspective)

You can download Portping from here.

It enables you to check the qualities of "ICMP, TCP and UDP" connections.

Basic command

portping [-c <tries(count)>] <Destination host> <Destination port>

It has only one option -c: stop after count connections (default 5).

Thus, it's very simple to use.

For e.g.

Note! The name can be different depending on the version such as "portping-v1.0-windows_amd64.exe", therefore it will be easier to rename this file to "portping.exe" in order to use convenience. You need to perform this operation on the same directory whereas the executable files located. You can add the directory to your Path(System Properties > Advanced > Environment Variables > Path > Add directory of the file location)  Alternatively, you can copy the executable files to the current system directory e.g. C:\Windows\System32.

What else?

PsPing and Portping can be also useful to check the connectivity to the server for the specific services in a situation of ICMP(ping) protocol blocked in the target network by the administrator.

References

• Windows 10: Enabling Telnet Client
• PsPing
• PortPing download(Sourceforge)
• Other tools: tcping, nmap