What is NAT?
NAT is short for "Network Address Translation". The basic purpose of NAT is to translate private IP addresses which are used inside the company into public (global) IP addresses.
NAT is primarily used to conserve global IP addresses because it allows that many IP-enabled devices use a few public IP addresses. It's really easy to see NAT at work. For instance, at your work place you and your colleagues are probably represented by a single IP address and NAT allows you all to access the Internet at the same time.
To verify all this simply go on some What's my IP? service from yours and your friend's computer, and you'll see that you and your friend have the same IP address. In reality the address you see is the address of a router that runs NAT.
This won't be a very long article, it will instead be a first article in a series about eZ Publish CMS. eZ Publish is very robust open source CMS written in PHP, so there's no point in trying to encompass it in one article. This will be an introduction to the eZ Publish CMS and we'll get deeper into it's functionalities in some later blog post.
The need for CMS
I'm sure you're aware what a CMS is and how it can help you and your site be more successful. Just in case you're a newbie in Web Development, let me just say that a CMS can do wonders. CMS (Content Management System) can help you to create a website in a matter of minutes and then you can use it to edit your website content and add new articles.
As we all know, if the computers want to communicate with each other, they must be on the same network. In addition, every computer must be assigned an IP address. In large networks this can take a significant portion of administrator's and users' time, not to mention the possibility of assigning duplicate addresses and lost connectivity. And even if you configure everything correctly, it's difficult to add new hosts to the network. Or what if the employee moves to another part of a building? DHCP to the rescue!
What is this DHCP and where is it used?
DHCP stands for Dynamic Host Configuration Protocol. DHCP is a protocol that's used on to automatically configure the hosts on a network. In addition to configuring the hosts with an IP address, DHCP can also configure them with additional parameters, such as subnet mask, or DNS server address.
We’ll be creating a simple but fully functional website. We’ll use the design, HTML and CSS from one of my previous blog posts: Step-by-step walktrough for coding a Web Site from a Photoshop template. So, HTML and CSS are basically already done. Of course, we need to integrate these files into ASP.NET templates, so the basic HTML & CSS will be repeated.
So, the layout is almost done and beside integrating it into templates we have to develop the website functionalities. This time I’ll skip the image gallery part, because I believe something like that needs a blog post of it’s own. We’ll add the image gallery and RSS another time, hopefully soon. :) So, the functionalities will include:
- About Me section with fixed content inside
- Last Blog posts on the home page
- Blog section with posts sorted into categories
- Working Contact form
So, we’ll steal some HTML/CSS from this design:
OK, let’s get into it!
I have been mentioning the GNS3 for last 2 Networking blog posts and still using Cisco Packet Tracer to show network topologies and Router Configurations. So, I believe the time has finally come to say a few words about GNS3.
After this, I will be able to use GNS3 in some future blog post about networking and not feel bad about it. :)
What is GNS3?
GNS is a shorthand for Graphical Network Simulator. GNS3 allows you the emulation of network hardware on your PC, similar to Windows Virtual PC. Windows Virtual PC enables you to run operating systems inside the virtual environment. You may have heard of Windows XP mode in Windows 7 for example.