First off your probably like, “What the heck is port blocking? And more importantly, why should I care?” Both valid questions.
Well we are here to tell you. Port blocking is put in place by your internet provider, your computers security software, your routers firewall, and other internet resources you access on the internet to protect them from attacks. But that can be also abused and misused if done wrong. We will be discussing how to check if you have been port blocked on a port you care about.
The reason you would care about port blocking is because you are having a web surf issue, email connection issue, or your trying to setup a web server from your home/office.
You can get a free port check tool from portfroward.com that will allow you to do what we are going to show you. You can also download it by clicking here. This is more reliable then running a web based port check many internet providers would have you run, because it actually does a full check of the port issue.
This is a fairly simple tool to use. Something to note, your router may not always be pingable even though it is working fine, this is intentional in some cases based off from your router manufacturer.
All you have to do is type in the port you are having problems with in the Port number to check spot, then click Check Me.
The port check result will tell you if you are blocked by something or not.
Open port example:
Blocked port example:
If you have a blocked port, you should try disabling your security software on your computer first. It is real common that it can cause issues. If that does not works, it could be your router blocking you, and lastly it could be your internet provider could be blocking you. If you are testing port 25, or 80 that is probably your internet provider causing the issue as they normally block those ports.
As you can see this is a simple but effective test to see if you are having problems with your ports being blocked.
Quick troubleshooting tip: If you think it is a router issue, and you have a independent modem, unplug your modem, and connect your computer with an Ethernet cable directly to the modem and power the modem back up. Rerun the test again with your security software off. If you have the same issue, then you are being blocked most likely by your internet provider.
Industry politics on port blocking: A little side note about internet providers, and what they teach/allow their staff to say. Most internet providers will not tell/allow their employees to admit to port blocking, so calling them and complaining is quite useless. It is part of their back end network security, and they are not going to discuss that with their customers for obvious reasons. So if you find you are being blocked on one port, you will need to find another port to work with.
If you are planning on running a home server, and you are blocked on port 80 our sister site Simply A Website has a awesome article on how to get around that issue, and a list of providers and ports they block. You can get to that by clicking here.