Dec 242011
 

For those who work on multiple Linux/Unix machines, we sometimes need to do work remotely. Sometimes the terminal doesn’t cut it, and we need to use a GUI application. There are a number of ways to view a GUI on a remote machine, but one way is by X11 forwarding through an SSH connection.

One problem with X11 forwarding, especially over the internet, is the slow speed. This post hopes to explain X11 forwarding, and ways to speed it up.

You can use the command:
ssh -c arcfour,blowfish-cbc -X -C user@192.168.11.3
To establish an SSH session with X11 forwarding enabled. Then all you need to do is launch a X program and it should appear on your local display. Before I explain the command, you must first have X11 forwarding enabled in your sshd_config on your server. Set X11Forwarding yes in your config file.

Now, for the SSH command:

  • -c arcfour,blowfish-cbc : specifies the encryption algorithms to use. These seem to be some of the fastest.
  • -X : This enables X11 Forwarding
  • -C : This enables compression
  • user@192.168.11.3 : This is the user name of the remote machine, and the IP address of that server.
Oct 312010
 

Hello Folks,
Long time and no posting. I’ve been quite busy. So here are some updates:

Updates

MCPM

I’m currently completing a Masters Certificate in Project Management. It is a four month course that prepares you to be a professional project manager. It has been an interesting experience. The skills I’ve learned so far have already been put to good use both at work, and with my business on the side.

Project Work

My company has been awarded a contract to develop a Document Management System, as well as install servers and software to support this system. Work will be starting next week, and I will have very little free time to work on anything else during this. šŸ™ But, it will be a great experience and our first big project!

Server Hosting

In the last month or so, the company I had a VPS with http://www.webserve.ca (BBB Rating: C – 121 Complaints) was constantly attacked and hacked by outsiders. No matter what lengths I go to, somehow, someone was on the server sending mail and doing bad things. It seems that the company does very little intrusion detection, and the way in which the server was compromised, I suspect that the virtual hosts were actually the source. After 12 hour downtime with no answer from their 24/7 support, I decided to return to my former web host (http://www.canadianwebhosting.com BBB Rating: A+ – 0 complaints). Although more expensive, their support has been fantastic, and quality/value of service is good.

Software Plans

That last piece is a great segue into my software plan section. During my migration, I had to move my database (obviously). That experience has pushed me to develop a script that dumps commands to recreate all of your users and all of your grants in the event that you have to migrate your mysql database. By running this script, you will get all of the code you need to recreate all of your users and grants. Coupled with a mysql dump, you should be able to quickly copy an entire database! Hopefully I will find some time in the next few months to write the code.

I’m also planning to write a simple script that will aggregate our logwatch reports from our 15 servers into a single daily report. Instead of the default function, which is to email, the logwatch report will be scp’ed to a central server, and then a script will go over all of the reports, and put something together for all of the servers. I’ll make this available once it is written.

Gaming

I’ve been playing a bit of Civilization 5 lately. It is an ok game, but I find it is still very rough around the edges. Lots of bugs, incomplete features, and terrible AI. Although I really do enjoy the new combat engine.

I’ve also been playing a bit of Urban Terror. A free realistic FPS available for Linux.

Software

I’ve also run across a few nice software packages that I’d like to recommend:
Adminer: A great PHP script that you can upload to your site, and gain phpmyadmin type access to your databases. Supports a number of database types. Allows you to execute queries, create databases, backup databases and just browse your tables. It is a single file, so there is no installation, and I intend to use it for some light DB admin work.

Firewall Builder: I was looking for a program to help me manage iptables on linux. I’ve run firestarter in the past, but that is a gui app, and I wanted to configure the firewall for a server with no gui. I ran across Firewall Builder and gave it a try. It is dually licensed as commercial for Windows and Mac users and free for Linux users. Being a Linux user, I jumped at it to give it a try.

The interface is a bit daunting for the first time user, I strongly recommend you watch the intro video (and hopefully you already know what a firewall does. ;)) This program lets you use drag and drop to configure rules for your firewall. It creates the rules in a custom format, and then compiles them into a number of different formats for various firewall programs and devices. It even goes a step further and lets you remotely install the firewall on the remote servers. A very nice touch.

I’ve only tried iptables configuration so far, but it ran very well. I intend to use it for all of our servers, and put the configuration files under revision management. So I can manage all versions of our firewall configs from a single box.

That’s all for now.

May 192010
 

Art…with ASCII you say. Well yes I do. Anyone from back in the day will appreciate ASCII art. Better yet is the ability to create ASCII art and diagrams easily. Enter the players:

asciio is a tool that allows you to easily make ASCII diagrams.

ditaa is a tool that converts ASCII art diagrams into rendered images suitable for webpages or publications.

These tools allow you to make nice rendered images and ASCII diagrams. As some have put it, ASCII Visio.

I’ve created a tutorial an how to modify asciio to better create ditaa diagrams. You can view this tutorial here: http://wiki.cornempire.net/asciiart/start Soon, many of these changes will be integrated with the package available with Debian Sid (and by extension, any Debian based Linux distribution).

The ideas for the modifications came from here: http://strawp.net/archive/geeking-out-with-diagrams-in-ascii/ and those ideas lead to the more expansive tutorial linked above. Thanks to David Paleino at Debian who has packaged Ditaa and asciio and may integrate some of these changes into the packages in the future.

If you use, or have interest in ASCII diagrams, leave a comment below.