A Brief Overview of NAT – Network Address Translation

What is NAT and how does it ‘translate’ an address?

NAT stands for network address translation; this is a process of modifying an IP packet as it transits a network.  This involves a router or firewall modifying the IP information in packets that are passed through the network boundary that is performing the address translation. The most common use of NAT is to translate a private address to a public addresses at a firewall/router, which separates an intranet network from the internet. As traffic originates from the internal side of the network boundary, the IP information in the packet is changed to a public IP address that is routable on the internet. Once traffic returns to the firewall, the NAT translations table that is stored on the device maps the public IP back to the private IP address, and forwards the information to the correct internal IP address that requested it.

While you can do different types of NATing, the most widely used configurations are dynamic NAT and static NAT. The most Continue reading A Brief Overview of NAT – Network Address Translation

How to Mount and ISO Image in Solaris and Linux

Why Bother Mounting an ISO Image?

Sometimes you find yourself in a situation where you need to take an ISO image and utilize it like a CD or DVD. The popularity of virtual machines and the ability to manipulate larger files over high speed Internet increase the chances that you’ll have to work with an ISO image from time to time. Being able to mount an ISO image as though it were an inserted CD/DVD can make manipulating these kinds of files a bit easier– especially if your computer doesn’t have a CD/DVD ROM drive installed.

In Solaris

Let’s say you have a third party program you need to install, but the vendor only gives you an ISO file. Let’s say the name of the file is thirdparty.iso and you have downloaded that file to /export/home/myhome. Here’s an easy way to utilize this file under Solaris: Continue reading How to Mount and ISO Image in Solaris and Linux

Amazon Web Services : RHEL 6.4 Setup

Although most of my test servers are registered with RackSpace, I thought that it would be a good idea to review AWS for some of my less technical colleagues that are interested in gently stepping into the Cloud Server arena. AWS offers a free tier service for 12 months using the t1.micro instance for 750 hours. However, a credit card will be required to setup an account so they may easily charge you if you decide to upgrade to another service level. Although this straightforward 25 step process will help you get up running with a RHEL 6.4 server, you should read the AWS documentation and FAQs to understand how the system works and pricing levels.

1. Go to the Amazon website and click “Get Started for Free“,

  http://aws.amazon.com/free/

aws1 Continue reading Amazon Web Services : RHEL 6.4 Setup

How to Sub-Delegate Reverse DNS Records Part 2

From the Service Provider’s Perspective

In part one of this topic, we discussed how to manage a sub-delegation for reverse DNS records once your ISP provides this service for you. Here in part two, we’ll discuss how to provide the sub-delegation of a reverse DNS range to another user. So in this situation, think of yourself as the provider offering the service for a customer or end user.

What You’ll Need

After you have received the request from the customer, you will need to confirm that they have created the proper zone for the Continue reading How to Sub-Delegate Reverse DNS Records Part 2