Ubuntu Idyll Cisco Study Environment

I have written a few posts in which I mentioned the amazing GNS3/Dynamips/Dynagen set of tools that enable you emulate a Cisco network …. also a great too used to prepare for the Cisco CCIE lab exam [Professor of Internetworking]

Here are a couple of things I have used that make creating and using labs a nirvana experience in Ubuntu … [constant flow for those who understand Emotional Intelligence]
1. Because I hate having multiple console windows open, one for each router which is the default behaviour of GNS3, I wrote the script [tamonet.sh] in the previous post that essentially takes as an arguement your topology (.net) file and then opens each router console in a separate tab in gnome-terminal.
2. I modified my gnome-terminal profile so that my background is translucent. That way, I can have a document (e.g a workbook) I refer to in the background and read instructions or make references without having to switch windows.
3. Initially, to launch my lab with my tamonet.sh script, I would open up either a terminal or the RUN application box [Alt-F2] and issue the command …. that is until I discovered awn-terminal. Boy! …. first of all, AWN is a cool dock application for Ubuntu and one of its applets is a nifty cool terminal that you just click and it pops up a next-gen-like translucent terminal. You just type in your command and as soon as u move focus from it, it automatically closes … no clutter on your desktop!!
4. And finally … when I am doing such work, I play music. Mozart is ideal for me but I generally prefer any kind of music without vocals. It is the vocals I find distracting. So for me, to complete the ensemble, it is Mozart, Beethoven, Tchaikovsky or soundtrack music [Prison Break, Stargate etc]

Given what I mostly do these days [putting in my 10000 hours to master my craft as a network engineer] and my passion for Ubuntu … I enjoy every single moment I spend building and executing scenarios and everyday, I say thank you to the guys who selflessly make all this possible …and it reminds me to keep sharing what little I know. Happy Valentines day guys and babes … do spend vals with someone real … far away from your laptop ok?

Fixing the Menu Editor in Ubuntu

I had my shiny new 64-bit Ubuntu 8.10 up and running and then decided to do some arrangements on my menus  and behold … I would right-click on the Ubuntu icon and select Edit Menus but nothing would happen. Even a trip to Preferences->Main Menu was unresponsive. Well, I know that the program that does menu editing in Gnome is called alacarte, so I decided to run alacarte from the command line and that is where I discovered the source of the problems. U see during setup, when u choose you language and country, Ubuntu setup uses them to decide your locale, so in my case my locale turned out to be en_NG (Nigerian English) and that was just not an acceptable locale to Python (the programming language in which alacarte is written). So how do you fix it? … simple, just set your locale to one of the mainstream (whoever decides that, I don´t know) ones, in my case, since we actually use British English.

Go to Settings.Adminstration.Language Support. In the Default Language section, choose English UK, or English US.
I suspect that French France, Spannish Spain etc would work for the other major languages.

With those settings, just log off and log back in (or better still just reboot) and your menu editing woes will be over.

For the curious, with my choice, my locale became en_GB (or is it en_UK?) which was an acceptable locale to Python.

Displaying a Host’s Active TCP/UDP Sessions

Ok, suppose your sleuthing aroung with ntop finally identifies a particular host as the major consumer of bandwidth, what if you want to find out just what exactly s/he is doing online that is consuming so much bandwidth? Here is how ntop can help:

1. Identify the host you are interested in [one way is to sort on the Data for Network Traffic stats for local hosts.

2. Click on that host to bring up the Info about xxxxx page where xxxx is the name or IP address of the host you are interested in.

3. Scroll down to the bottom of the page to the Active TCP/UDP Sessions table. A screenshot is shown which "lays it all out for you". It almost something like you'd get running netstat on the host albeit cuter?

 

Active TCP/UDP Sessions for a Host

NTOP Bandwidth Monitoring on Ubuntu 8.04

I have been working on deploying the latest version of the popular ntop bandwidth monitoring application. Here is a guide I wrote to get other started. I will make updates whenever I learn new things on this blog. You will also be able to download the latest copy of the guide from here.

ntop Guide 1.1

I think ntop is a brilliant tool for seeing what is happening on your network in realtime. It is Open Source, Free [as in both free speech and free beer] and in active development. Check back on this page not ony for latest copy of documentation but also for some screenshots and use cases for ntop as well as other cool stuff I come across.