Good all in one source to understand computer networks

I am looking for a book, a website or a blog which takes one from the basics in layman terms to the advance topics in computer networking. I mean practical networking. Like what are ports how are they used, how are they exploited, are there any alternatives, etc. I don’t want long theoretic explanations. Just quick useful definitions with practical usage examples. Practical usage should be primary aspect of the source.
I am looking for an all in one solution which encompasses almost all the topics. Thanks
Answer #1
I don’t know any such site but I can provide a fairly brief explanation on this,Ports are virtual listening sockets who can accept local or remote connections,It depends on which interface the particular application is set to listen to,And of course whenever there’s a router involved and remote access to the particular port (over the internet,not local network) is required,Port forwarding has to be done as well as properly configured any software firewalls to allow the app. Each port uses a specific number such as 1234,There are two protocols which ports can use and those are TCP & UDP (with the first one being much more common) A port number can’t be higher than 65535,That’s the limit. Ports that can accept remote connections are most commonly used by server applications (With protocols such as FTP,SMTP,POP3),A port by itself can’t just be “exploited”,There has to be a certain security loop hole (more commonly called vulnerability) in the particular application that uses it.
Answer #2
Google?
Answer #3
if you know anything about computers look for comptia network plus. it will teach you all about networking.
if not look for comptia A+ which is the very basics of computers
Answer #4
The best way is familiarize yourself with the OSI network model. Learn the 7 layers and their roles.
http://en.wikipedia.org/wiki/OSI_model
Answer #5
comptia might be the thing I am looking for. Thanks all