Check Open Port

IP Address
Port
Default Port for Internet Apps
80 HTTP
443 HTTPS
143 IMAP
21 FTP
22 SSH
110 POP3
25 SMTP
Default Port for DBs
1433 MSSQL
3306 MySQL
5432 PostgreSQL
3050 FireBird
1521 Oracle DB
Default Port for Apps
23399 Skype
5938 TeamViewer
(6665-6669) IRC
8200 GoTo MyPC
5050 Yahoo Messenger
Default Port for Popular Games
10050 PlayStation Network
3074 Xbox Live and Games for Windows Live
25565 Minecraft
2700 Steam(Game Client)- 27000 - 27015

About

Check Open port allows you to check your port forwarding issues. You can check if the port is open from the internet using this online utility. If you are running a webserver, you need to ensure port 80(HTTP) is open on your IP which can be verified from CheckOpenPort.com. In addition to this if your router does not support UPnP you will need Portforwarding to make some of your applications to work.

What is Port Forwarding ?

Port forwarding allows remote computers to connect to a specific computer or service within a private local-area network (LAN)

Why do I need it ?

When you want to expose a service available on your Computer to the internet. Let's say you setting up a Minecraft Server to play with your friends.

How to forward Port for my router ?

You will need to modify your router configuration to allow Port Forwarding. The easiest way would be to search Router Model Number and Port Forwarding on google.

Further Reading on Wikipedia