HOWTO: Clear the DNS Cache

When you use DNS to resolve hostnames to IP addresses or services end point addresses, and you make a change in your domain zone configuration you have to reload the cached records on your devices so the new addresses will be used for processing. You have two options:

• wait while the DNS cache of your device will expire and your device will send a new DNS query request
• clear the cache manually

On Windows you can clear the DNS cache with the “ ipconfig /flushdns ” command.

On Cisco gears you can use the “ clear hosts * ” enable mode command.

Firefox 3.0 is out!

It’s still not available through www.getfirefox.com (it will be from 10:00AM PDT {19:00 CET}) but it’s already available on the official FTP server.

Get it from ftp.mozilla.org/pub/firefox/releases/3.0/win32/en-US/Firefox%20Setup%203.0.exe

Run Linux (or Windows) in your Cisco ISR Router

Sounds good isn’t it? :) I remember the times when I flashed a Cisco 2500 series router with a ucLinux image. It was nice to see Linux booting on a Cisco router, even tho’ it was unusable :-( The interfaces didn’t work at all, the only thing that was working was a console access to the Linux CLI.

But this time I wanted to write about something different. Cisco was already using Linux as a base operating system on several products like Wireless LAN Controllers, ASA, etc. Cisco has lately announced a new Network Module (Cisco Application eXtension Platform (AXP)), available for Cisco ISR series routers, that contains a small motherboard with CPU, RAM, and a Hard Disk Drive.

The great thing about the AXP module is that there is preinstalled a fully functional Linux (and I have heard that there is also a Windows 2008 Server version) operating system with basic tools. What’s more, there is an API that allows you to create your own Linux applications that will directly interact with your Cisco ISR router. And as Cisco ISR routers are designed to be used in Branch Offices, now you can pretty easily integrate your email server, or whatever simple Linux (or perhaps Windows (Domain Controller)) application into a single box, thus saving space, electricity power and making your network services management much more simpler!

To find out more about AXP, please go to cisco.com/go/axp

HOWTO: Paste clipboard contents to a CMD.exe window

It was screwing me that when I was working in Windows Command Line interface (cmd.exe) I couldn’t use the CRTL+V or Shift+Insert combination to paste a text from the clipboard. I always had to use the mouse pointer, right click and the paste option from a contextual menu. That was really annoying :-(

Fortunately I found a solution that makes this paste process much more simple:

It’s a bit tricky, and it may take some time while you get that combination into your fingers, but it works :-) So the “magic” keys combination is: “ALT+Space e p”. That is, first press the ALT and the Space key at the same time. A window menu will be shown:

Then press the “e” key. That will move the selected menu option to the Edit>. And finally press the “p” key to paste a text from the windows clipboard.

It’s just that simple. Made by Microsoft to be user-friendly :-)

Write Code: Mind Wide Open

I was talking with a friend of mine about some programming stuff. He has got a school assignment to develop a simple game in C#. Well, the first thing that students usually start with, is that they buy a book about C#. They read the book, and when the last page is over, they start with the development of their fabulous application. Now they know a lot of C# commands, structures, objects, we could maybe say that some of them are now even C# gurus (at least they know a bunch of commands). Now there is a problem. Many times I face people that even tho' they know HOW to write code, they do not know WHAT to write!

Many times they are missing the essential imagination of the application's building blocks, relations, dependencies, application flow, etc. My suggestion for this case is to grab a pencil and paper, forget everything you know about C#, open your mind and start drawing and designing your application.

You can start with the user interface. If you know that the game will be the minesweeper, draw a basic window, control objects, the minefield, etc. Then start with the application analysis. Within the analysis you have to understand what must your application exactly do. After finishing the analysis part, you should have an activity diagram, that will clearly display what actions may happen in you application and how to handle them. This part was the platform independent analysis. For this part it is not necessary to know anything about C#. As you will go deeper and deeper, your drawing will became more and more platform dependent, and for this game it should end up at the .net and C# platform.

So continue with deeper analysis and create the architecture of you application. Start thinking about building blocks of you application - basic classes, interfaces, methods, their relations, dependencies, etc. Draw everything to your paper and take notes. Supporting applications like MindManager or FreeMind may help you to collect your ideas and don't forget anything.

After having completed all these steps, remember all the things that you learned about programming in C#, take a look at your drawings and notes, and now you should know HOW and WHAT to write to your source code!

A successful analysis at the beginning is about complete understanding of the application and it ensures that at the end of your application development you should not end up in such a situation as it is displayed on this ^ picture :-)

Skype into Pidgin

Eion Robb has created a plugin for Pidgin which integrates Skype contacts into Pidgin. After installing and setting up the plugin in Pidgin, you can use Pidgin to talk with your friends on Skype. I love it!

Download.

Launch your Launchy

I have included a Launchy called application in my previous blog post about my favorite Windows applications. And I think it's even worth to write a custom blog post about this fabulous application launcher.

Launchy is an interactive application launcher for Windows. It's like the Start->Run menu on very powerful steroids, and maybe even a bit more. After the first launch of Launchy, it created an index of applications in your Start menu and Desktop. When the indexing is complete, you can press the hot keys combination (by default ALT+SPACE) to bring Launchy's window into the front. It will bring up a nice looking window where it's enough to type just few starting letters of your application and it will start it. I really recommend to give to this application at least a try :-)

andLinux

No, there is no space missing between the "and" and the "Linux". The andLinux is a Ubuntu based Linux distribution which is very special in one way - it runs directly on Windows. How? Well, here is the answer: the project is based on coLinux (cooperative Linux).

CoLinux is an older project which has ported the Linux kernel to a windows executable file. So you can start the Linux kernel as a standard win32 file, and with some special additions you can add disk storage, networking, etc. Sounds good, doesn't it? :-) In this way you can start your Linux system whenever you want, while you are in Widnows. No need to reboot to Linux (e.g. dualboot), or start vmware or other virtualization technique.

Well, so the guys behind the andLinux project has created a Ubuntu installation which runs on top of coLinux. But not just that. They have also added some additional tools from their own garage, like they have added sound and graphics support (x11) and even more - you can for example open PDF files on your Windows's My Documents folder with a xpdf started trough andLinux. And the best thing is that it's all packaged into a nice, user-friendly windows installation package so even a non computer geek can install it without bigger issues. It's really amazing! Guys, you have done a really great job!

You can access andLinux at andlinux.org.

M$ always brings a smile to your face ...

... if not by creating a stable operating system (well, I have to admit that XP and 2k3 are pretty good), then by creating a funny ad. I was browsing around some news sites and found a nice post about a new Microsoft book. This new book was designed for children and their parents to explain and understand why it is not a shame to have a server at your home (Who is the PR manager at M$?). Well, I "think" it's really a matter of life to explain to kids that a home server is nothing wrong, it doesn't make you nerdy and the other kids are making fun of them just because they are jealous and they want to have a home server too. Really, a book about a computer security would be much better and more useful than this :-/ http://tinyurl.com/2yq5u3

Putty feature - Putty authentication agent

Using RSA/DSA key pairs (public and private key) for SSH connection authentication has many advantages. It makes the authentication process more secure (especially when someone can see what are you typing on your keyboard), it enables using automated scripts for backup, etc. Under Windows you can generate RSA/DSA key pairs for ssh connection with the PuTTYgen application.

If you already have your RSA/DSA key pair generated, you copy-pasted the public key to the server to ~/.ssh/authorized_keys, then you can use the private key as an authentication mechanism instead of a password. If you have generated your RSA/DSA keys with a passphrase (I recommend to generate it with passphrase enabled) then you will be requested to enter it while authenticating.

Sometimes you have to connect to more servers at once, and have to enter the passphrase or a password as many times as many ssh session are you creating. To overcome the need of entering the passphrase, you can use the Putty authentication agent.

Start pageant.exe. A new Pageant icon will be added to the system tray:

Doubleclick on the Pageant icon and a window similar to the following figure should be displayed:

 

The Pageant window contains a list of enabled RSA/DSA keys which are automatically provided to putty or scp applications for RSA/DSA keys based authentication of the SSH session.

Click on Add Key and search for your private RSA/DSA key which you are using for SSH. If you are using a passphrase in your private RSA/DSA key (I highly recommend to use it) then just enter the password and the private key will be added to your enabled keys list.

That's all. Now if you try to connect to your ssh enabled host, your ssh connection authentication may look like this:

and a scp file copy may look like this:

!!!BEWARE!!!

Do not forget to lock your computer screen when you are leaving it and you have RSA/DSA keys enabled in Pageant! Otherwise anyone who has physical access to your computer can connect to your servers with ssh without having to know your passphrase.

My favorite Windows applications

• firefox - the Best web browser ever
• putty - ssh, telnet client
• wireshark - network sniffer, useful for troubleshooting
• vmware - virtual machines
• launchy - windows quick lunch replacement on steroids and much more
• objectdock - windows taskbar replacement
• mspaint - the Best pictures editor :-p
• irfan view - the Best pictures viewer ever!
• pidgin - multiple IM networks client (icq, msn, irc, gtalk, ...)
• super - super video converter, it can convert anything to anything :-D
• TextAloud - text2speech, read the webpage in your browser
• Shareaza - P2P client used to download high quality legal stuff
• Picasa - pictures/photo management software, can upload pictures to picasaweb
• Packet Tracer 4.1, Dynampis, Dynagen, GNS3 - if you work with Cisco this is the definitely must have stuff!
• OpenVPN - VPN solution
• Outlook on desktop - display your outlook calendar (tasks, emails, ...) on your desktop
• Notebook Hardware Control - control your processor power consumption
• Nero - burn burn burn
• Mindmanager - manage your ideas easily
• Visual Studio - develop .net or C++ applications
• Last.fm - listen your favorite music, show other what are you listening
• K-lite mega codec pack - the Best codec pack for Widnows
• Virtual Dub - avi video files editor
• Express talk - VoIP client
• xlite - VoIP client
• Nod32 - the Best antivirus solution ever!
• Debugging tools for Windows - Debug your buggy Windows and find out what's wrong
• Norton Ghost - disk backup solution
• HySnapDX - screenshots easily
• Notepad++ - the Best text editor ever!
• wipfw - FreeBSD firewall on your Windows
• Process Explorer - must have Windows Task Manager replacement
• scp - securely copy your files from command line
• autoruns - check what applications are being started with your computer and more
• filemon - monitor what happens to your files
• regmon - monitor what happens to your Windows registry
• pagedfrg - defragment your page file, registry hives, ...
• tftpd32 - the Best ever TFTP server
• tcpview - what networking applications are running
• junction - like Linux symlinks, but this on Windows and NTFS
• nc - no, not Norton Commander but NetCat
• vitrite - make any window transparent
• MACAddressChanger - easily change your MAC address
• UnxUtils - unix command like tools
• Media player classic - must have Media Player for movies
• VideoLAN VLC - play any video in this player
• Demon tools - mount your ISO images into a virtual CDrom drive
• cutepdf - print anything to PDF
• CrossLoop - Connect to a computer screen remotely
• Google desktop - Google your local files
• microsoft.net - great application framework
• Network Stumbler - find your neighborhoods WiFi networks
• Serv-U - FTP server
• Skype - VoIP client
• TaskSwitchXP - ALT+TAB on steroids
• Windows Defender - defend your Windows from Spyware
• WinRAR - un/pack and de/compress your files
• Zend - PHP developer's Swiss knife
• Microsoft Office Outlook 2007 - Manage your email and calendar from one place
• Visio - draw nice diagrams
• notepad - nice tool for small notes

What are your favorite Windows applications?

Print multiple labels per page and use an external data source

Today was somehow a special day. The reason why was it special was an inventory check at CNL. This is always a special event because we usually find on the inventory list some things which we have never seen or even heard about :-)

Anyway, on this year we wanted to put some new labels on your equipment so in the future they could be identified more easily. We bought some A4 pages, each page with 40 stickers. The idea was to print to these stickers with some labels (ID numbers) which will then identify our equipment.

The first problem was finding a software which could be easily used to create these stickers. At the end, the Microsoft Publisher 2007 was used. It's a pretty good piece of software, which can be used to create good looking presentation materials, papers, business cards, labels, etc.

So I started Publisher, created a new project based on some label template. First I changed the size of a label. We had 40 stickers on A4 paper, 10 rows and 4 columns. So one sticker has 5,25cm per 2,97cm size. The I adder our logo figure, some informational text and as last but not least the ID number. Our department uses 8 digits (ID) to identify any equipment and it looked to be a good idea to follow this rule and create these stickers with 8 digits identification code. The year of the equipment acquisition is also important for us, so it has to be visible on a sticker too. So far so simple.

What we needed be then was a dynamic data source with IDs, years of acquisition and other information. This data source was an Excel sheet.

I found on the Microsoft Office web site a great step-by-step guide which describers how to create different labels on the same sheet. Exactly what we needed :-) It's enough just to follow up that guide (the automated method section) and you will be able to create nice labels and stickers with text based on a data source found in XLS file, SQL database, TXT file, or any other Office compatible data source.