Tag: fedora11

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not many people have access to networking hardware and even if they have it, the hardware is usually quite old or outdated.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.

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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.

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