Setup SSH Key Authentication (Password-Less Authentication)

Setup ssh key authentication for password-less login between servers.  For use by ssh/sftp users or scripts.

Source Server (or local system)

Generate RSA key for user on this system, you can also use DSA.  This asks for key pass-phrase but you can leave it blank.

ssh-keygen -t rsa

This asks for location to place the generated key, by default it will be your home directory (ex: /home/your_username/.ssh/).  This generates two files:  id_rsaand id_rsa.pub.  Content of id_rsa.pub is what we need to copy to destination server.

Restrict network access by time or IP address with Squid

There are a number of reasons why you would want to restrict network access. You run a cafe with web access or you have young or teenage children and you want them to only be able to use the network at certain times. Their are certainly tools out there to do this on a PC-by-PC basis, but why not employ a proxy server instead? One of the best (and most robust) proxy servers available for the Linux operating system is theSquid Proxy server. But don’t let the name fool you, you do not have to install Squid on a server. You can just as easily install squid on a Linux desktop machine and control network access from your LAN.

Of course when you open up your /etc/squid/squid.conf file you might be a bit overwhelmed. So in this article I am going to show you two ways to limit access with Squid (instead of tossing the whole configuration file at you at once). I will also show you the quick and dirty method of installing Squid on a Fedora 13 machine. Once done with this article, you will at least be able to control network access by time or by IP address. In later articles we will discuss other ways to control network access with Squid.

Vinagre remote desktop connection for Linux

Do you administer Linux machines? Or do you just need the ability to remotely connect to your Linux machines from other Linux machines? If so, are you looking for an easy solution for this task? There is one, if you are a fan of the GNOME desktop.

Vinagre is a remote desktop tool with plenty of features and ease of use for just about any level of user. It’s enjoying release 2.30.1 so it’s quite mature. In this article I will show you how to install and use the default GNOME remote desktop tool.

Features

Vinagre offers enough features to help make it stand out among other rdp clients:

See what images are being viewed on your network with driftnet

I want to preface this article by saying I am not, in any way advocating spying on your users. With that said, there are times (and reasons) why you might need to see what images are being viewed on your network. Whether it be an end user who is viewing content that goes against specific company policies or, worse, against the law. When this happens, you might have need or cause to see just what is being viewed from your LAN. When this is the case there is a handy tool for that called Driftnet.

Driftnet was inspired by the old Apple program EtherPEG and works by watching TCP streams for images and MPEG audio streams. As it listens I dumps the images into a user configured directory and/or it can display the images within a window as they are captured. In this article I will show you how to install and use Driftnet.

Installation

Connect remotely from Linux with Terminal Server Client

I do a lot of remote work throughout the day and to make those connections I use different tools. Between LogMeIn andTeamViewer I have remote support covered. But when I need to connect to a machine such as a Terminal Server, where do I turn? Generally speaking I turn to the Linux tool Terminal Server Client (tsclient.) This tool makes connecting to unattended remote servers a snap — and it workswith different protocols.

Features

Just what does tsclient offer? Take a look at this short list of features:

Network Troubleshooting Basics: Tracert & Pathping

This article is the third in a series of the basics of network troubleshooting. So farping and ipconfig have been covered. Now tracert and pathping, which are similar commands, will be covered. While this is a basic tutorial, there are some intermediate tips and topics included. The focus will be on Windows based systems(with a tip or two for other systems).

Both of these commands are designed to give you more detailed information than the ping command. They will tell you about steps along the way. This can help you narrow down where a problem is.

The Tracert Command Basics

The tracert command is also called traceroute on other systems, such as on a Mac or in Cisco’s IOS (used in its routers and switches). It is used to find out what other devices are on the path to a destination. It works by sending out a number of signals. Each signal has an amount of locations it can jump to, called a time to live (TTL).

Network Troubleshooting Basics: Some Simple Steps

This article is the fourth and final part of a series on the basics of networktroubleshooting. The tools covered in the previous articles (ping, ipconfig, tracert and pathping) will be combined into a troubleshooting method. This guide will teach you valuable steps in finding where a problem is on a network connection.

One of my networking classes included the basics of troubleshooting a network connection. It included basic command line tools that really were very easy to use and understand. Most of the students thought they were fun to use.

Knowing these commands before having to deal with the frustration of a network connection problem is not a bad idea. A working connection shows you what is supposed to happen. If you see something different, you will know something is up. When problems strike, at the least you can get an idea of what is going on.