Archive for the ‘Networks’ Category

My toolbox – an incomplete list:

MTR – Link Diagnostics
IPerf – bandwidth test
TCPTrack – track tcp connections per interface

An indespensbile trouble shooting tool is MTR. It is already a part of my favorite distro, Ubuntu. It combines the functions of ping and traceroute, and the info provided is excellent for diagnostics. More at: http://www.bitwizard.nl/mtr/

Just use it in place of ‘ping’. For example:


This will update your terminal display with:

– Packet Loss %

– Packets Sent

– Ping, Last Response Time

– Ping, Average Response Time

– Ping, Best Response Time

– Ping, Worst Response Tim

and my favorite

– Ping, Standard Deviation


The gold standard for bandwidth testing. In Ubuntu:

sudo apt-get install iperf

To use, you need one session running as the server, and another (or several) as the client.

A quick example:


iperf -s -D

this command will run the server


iperf -c -r -t 30 -P 3

this will connect to a server at IP, and perform a two-way test for 30 seconds each. The -P 3 is interesting, as it will run 3 parallel processes to get full bandwidth results. This is especially useful on a Windows system, and a single connection test won’t be able to pump out the full bandwidth capabilities.

The results are quite useful.


Quick reference to active connects on an interface.  Excellent on a proxy/ router to monitor who might be using to much traffic

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I’ve been in the IT industry for almost 15 years, and worked with both large and small companies. I have never had an opportunity to work with the BGP protocol, until now. My experience with it has been fun (for a nerd), and I have now expanded my networking knowledge, just a little bit, so I want to share with you what I have found. I am by no means a BGP expert now, but can confidently understand and configure a somewhat complex arrangement with it.

As with all things for me, it would have helped immensely if there was a step-by-step example of how to complete my project. I learn by example, and can understand something if I can see the completed work first. So, I will provide that for you here.

Of course, I will be using open source tools – old hardware on Ubuntu Server 7.10, with Quagga. Clean, simple, stable, reliable.

Details to follow soon…

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