Revolution

i am happy to say that I am moving to my own hosting.

Since now, this blog will be hosted at http://tech.tiamat.name

All further updates will appear there only. Current blog account will be disabled soon. Thanks.

Dynamips, Dynagen and GNS3 as a Best Free Tools for Cisco IOS Learning

Boson NetSim and Packet Tracer are two examples of good Cisco networks emulators. They provide you with an opportunity to build networks of switches and routers, interconnect them and deploy several features of IOS. Good enough for beginners, but they have a huge drawback – their IOS simulation is limited. It does not implement a real set of functions real IOS has on board.

Several years before, the only opportunity to play with IOS was interconnection of real Cisco switches/routers. I still consider it was and still is a best way to learn Cisco. Unfortunately, not many people have access to networking hardware and even if they have it, the hardware is usually quite old or outdated. It means that you can run old versions of IOS there.

There is another approach of getting access to operational IOS – running it on a virtual machine. Emulating router’s hardware is not a straightforward task – Cisco uses different architectures in their devices. However, the task was accomplished in Dynamips/Dynagen project. It emulates Cisco hardware in a way so you can real IOS images on top of it. It is suitable to support 3600, 3700 and 2600 series hardware. Both pieces of software are closely interrelated and running together, providing users with a robust CLI interface.

Do not be frightened – CLI is not the only way of controlling your Cisco virtual machines. The tools have a graphical interface – GNS3. GNS3 runs on the top of Dynamips/Dynagen packages and provides GUI for controlling every virtual machine, machines interconnection, their modules and graphical network topology representation. It simply does everything that other graphical simulators can do.

Fedora 11 KDE4.3 Touchpad Scroll Activation

Problem: My touchpad’s scroll did not work under Fedora 11’s KDE. Also, I did not have any touch pad settings in Control Manager

Cause: By default, KDE4 under fedora 11 is missing touchpad settings package.

Solution: install kcm_touchpad package.

Beautiful Palette Generator.

Sometimes a task to design a simple web page arises. First step is designing layout of site. Second step is designing color palette. For me personally it is always a most complicated step which can be accomplished with an external help only. Lately I found a beautiful helper – http://colorschemedesigner.com/.



It simply does everything. You just need to choose a color and color layout type. The rest will be done by software. It will offer you to adjust layout, to see sample designs on HTML page, to export designs in several formats and make you coffee. I recommend.

WordPress as a Perfect Livejournal Backup Tool.

I have a livejournal account. Being system administrator, I am concerned about backup. But oops! Built-in livejournal backup tool is a mess. The tool tries to be as much inconvenient as possible. It allows you to export posts for a period of one month at once only. For a perin of one month only. ONE MONTH ONLY.

I’ve been looking around for another utility to backup my journal. Useless. None of them worked for me in a proper convenient way. No, my demands were not impossible to satisfy. I wanted to import posts only. No comments, no visibility – only texts. I gave up and did my backup using native tool (arggh).

Greet the savior! Ave WordPress! It can import all your livejournal including hidden posts and all comments with a status of their visibility. You’d say, ok I have imported it. What is next? Well, you can stop at this point. If you used WordPress.com, you can keep private copy of your livejournal, or you can hide all posts and use wordpress.com as your online storage (security!).

I’m not done yet. You can export your wordpress contents as XML file. And if it contains you livejournal copy, you already understand me, don’t you? Yes, it’s Profit.

Twitter as a News Source

There is a new trend on the internet. Every web site creates a twitter account and posts tweets about web site updates. Since there is an RSS present for years now, I find the whole idea ridiculous. There are three reasons why I find twitter updates useless:

1. They duplicate information, distributed by RSS.

2. Tweets are not complete updates as delivered via RSS, but only few words and link to the post. In other hand, some web sites do not deliver whole content through RSS, but it is a rare practice.

3. Link, delivered by Tweet, has to be clicked. It means, that one extra click stays between me and desired update. Also, the link is shortened by a we service and meaningless. Clicking the link, I do not know, where will it redirect me. Occasions, when I was transferred to spam or harmful sites, happen.

If I subscribe to news source, I want to receive updates in a fastest and fullest way. Twitter restricts this freedom. Be happy. Use RSS.

Learning C++ as a New Language

Yesterday I digested learning C++ as a new language paper by Bjarne Stroustrup. I am looking for a “correct” approach to learn programming. Programming science is giant mastodon. Programming is so huge system that it can’t be observed completely even after years of research. There are no professionals, who know all kinds of programming. Even old specialists with several areas of expertise observe only piece of puzzle. My target is to find universal guide into all, or at least most kinds of programming. A guide, that observes the whole mastodon and popularly describes every part of it.

However, the paper was not about my search. The paper is a good introduction into C++. It does not describe syntax of language, but provides a manual, guiding where and how to start learning the language. I noted, that those advises do not apply to C++ only, but applicable for any programming language. The paper is highly recommended to students, who are completely new to programming, as well as to teachers, creating their teaching programs.

I want to note, that if my teachers trained me according Stroustrup’s advises, educational effect would be higher. At least, i wouldn’t have had to discover a difference between standard library and language syntax myself. So if you are not satisfied by your teachers. but not sure where to start this paper is for you.

Speed up Firefox 3.5 on Fedora 11.

Since I moved to Fedora 10, I noticed Firefox became noticeably slower than before. Start-up was taking about 30 seconds. Even right click menu appearance had noticeable delay. I suspected plug-ins. I minimized amount of my plug-ins twice. It didn’t help.

After I suspected history and private data database. I tried to clean up history manually, but it did not decrease its size. Deleted entries were just marked as deleted, but kept remain in database. There was the last hope – trying to delete places.sqlite file manually. I had a hope that Firefox checks existence of database and recreates it in case of absence. And yes – it does it! It increased starting speed for about 5 seconds.

To eliminate large-history-problem in the future, I set a limit on it. You just need to go to about:config page and set a search filter to browser.history. Th following values need to be changed:

browser.history_expire_days;

browser.history_expire_days_min;

browser.history_expire_sites;

Personally, I set them to 30, 15 and 5000 accordingly. You may choose another values.

My last concern was language packs. There are all possible language packs installed and enabled by default in fedora’s Firefox. I disabled them all (a lot of clicking), except Russian and English ones. Miracle! Firefox starts up several times faster! Now it takes about 7 seconds only!

Windows and Linux System Time Shift Fix

Recently, I had to install Vista on my laptop. After installation I found that system time in Linux and in Windows had 3 hours difference. So every time I was rebooting into another OS, my system time was set on another value. To track time, I am always using clock in the tray. So changing clock value after each restart was really annoying.

Windows does not change sytem clock value, it changes output on system tray’s clock value according timezone difference only. Vista did not change any value on system clock. It was showing whatever value was left after Linux. Linux was not changing any clock value also. So problem was in time representation in both operating systems.

Occasionally, Linux can represent clock value in UTC, as well as in local time format. In my case, Linux was interpreting value as UTC, and converting it to local time. But windows was reading UTC value of clock, remaining after Linux, thinking that it is a local time, adding timezone difference, and viola! I was getting my three hours difference. Apparently, Vista can not understand that clock is UTC. So I just changed clock representation in Linux.

# clock --localtime

Cracking a WEP on HP Pavillion dv6k, Powered by Fedora 10

Introduction.

I was interested in wireless security since I have read some articles in “Xakep” magazine several years ago. They were saying “Most wireless networks are vulnerable and can be cracked within a day”. It was quite embarrassing that such a security threat can exist and really wanted to check whether it was true or not. Those years I did not not have any piece of needed experience. The task to crash test WEP stayed in my mind for years. Recently I have tried it.

Disclaimer.

All material is presented for educational purposes only. Do not apply this material’s guidelines in real life on real networks. Especially the ones, which do not belong to you.

This in not a how-to. This is a description of my experience. I do not guarantee, that process and steps, described here, will be applicable in your case and that it will work for you as well as it worked for me. I am not in charge of your failures.

System used.

I have used HP laptop with Intel 3945 wifi card installed, powered by fedora 10.