Open Port Check Tool is a tool that can be used to determinate the state of a port on a target device, as there are more than the usual 2 default states, re open and closed, there are advanced tools that are capable to also tell you if the port is filtered by any kind of filtering software, like firewall or other IDS (intrusion detection system).
As we, the end users, installed all king of software, on our computers and also on our mobile devices, without the thinking about what the software to except the trivial that is was meant to do, a lot of the software use the internet to do some more things from your computer or mobile device, on mobile devices, some tools request far more option then it really needs it is also true for computer base software that ask for an admin privilege to run, i know security tools need to have admin privilege to remove malware files from the system, but other tools that not always need the admin privilege also ask for it.
Most of us, give it this privilege…
Think about a game that you downloaded to your mobile device and it need to connect to the game server, most of today games have some sort of multiplayer aspect in them, and that mean the game – also a software – just open a port to make the connection and its sing it to transfer data between your mobile device, the one with all your contacts and other private stuff, to the server, and you just gave it an admin base privilege to do it.
This is also true for other application that communicates with a server, even to check for updates….
So, should we stop download tools, games, application that uses the internet?
No, and that is due to the fact that if we will, we will be unable to use most of the tools, games and applications, both mobile and computer base.
BUT WE DO NEED TO BE AWARE THAT THE APPLICATION CAN DO THAT!
We can use online and offline tools to scan for open ports, it can be our computer or our mobile device, after all both of them use an ip address to enter the internet, this is how it works, so if we use a tool to scan for open ports we may know what are the port that currently open.
So an open port scanner can tell us what ports are open on our device, it can test port open and show us what port respond to the test, re open and what port did not respond to the test, re closed.
What is an open port test?
It can be a method that we can use to check open port it can also be an open port check tool that we can use, so there are two main open port tools that we can use.
- Online port scanner: an online tool can be used from outside of your network to check if ports are open on your device, most of the tool can give you a status of open or close for the port or list/range of port that you test. The big advantage of an online tool is that it act like a real hacker because it come from outside your network, it’s like opening a locked door in your own home then going to other house in the neighborhood and open one of the inner doors.
- Offline port scanner: this is a tool, software, that you install on a local computer, or other device, it depend on the tool, and using some clicks or parameters its running and scanning the target devices, or devices for open port. There is one great tool, free that cab be download from the web, more about it later on.
The Open Port Free Tool:
As you may already try, in this site there is a free online open port scanner that can be use to check if a port is open or close, it use the connect function to see if the target port is open, we are planning to add more capabilities in future version of the tool to improve the scanning options and to add more tools to the site, some will be online and some will be offline, visit use from time to time to check, if you want.
The nmap port scan free tool:
For an external example there is an offline tool, free that can run both on linux and on windows operation system that call nmap, nmap is a shorten for Network Mapper, nmap port scan is far much more than a port scanner, it can do a lot more option with some build in parameters and even a script base language that can be used to create automatic tasks when using nmap port scan to scan target or targets devices.
Some of the nmap features are:
- OS detections.
- Build in script language.
- Scanning modes
- Scanning type.
- A lot of build in nmap commands.
The nmap tool can be download from here nmap download , and this is an advanced port scanner, and it’s free.
There are much more in nmap then this small paragraph and I do hope to add a post about it in the near future, with some nmap example and a tutorial and more, if you can use nmap as an offline tool, you can do a lot in the open port, or port scanning area as this is the leading tool in that area.
Local Open Port Checker:
Another aspect in related to open port and open port checker is the option to check on the local computer what are the current ports that are open and what are the state of the port that open and also who, or what service/process open them.
There is a build in command line tool that you can use to check it, and we do have article about it and how to use it, that call netstat , it is a command line tool that can output information about current open ports on the local computer, it include the port state, like listening and waiting for connections or establish, as there is an establish connection between the local computer to a target computer, I do recommended you to check the netstat post for more information about it.
There are some free netstat like GUI based tool that you can download and use to check states of currently open port on your system, an example of a tool is: TCPView By Mark Russinovich, that can be download from Microsoft web site: TCPView
Well I do gave you some nice information about open ports and tools that can be use to check the port state, hope you enjoy the reading and you can send us comments, thought, rejection and so on aout this post and about the web site, after all, the site was build to help others.
The OpenPort.net Team.