Simplicity is the ultimate sophistication

Font Size




Linux networking

TinyCore for GNS3 or VMWare

I needed to install a small footprint linux appliance for GNS3 and VMware (ESXi 6.5). I was not really happy with the VPC option in GNS3. Here are the steps I took to install this.
TinyCore is designed to wipe out at the next reboot any changes you have made to the OS. The idea is to have a system that will never crash. I guess it is designed for appliances that do not need to store any persistent data. This is not exactly ideal for a network appliance. So then why TinyCore? The answer is simple: it has a small foot print, works fine with 64M of RAM and no HDD if you want that or with a small virtual HDD .

Useful links

http://tinycorelinux.net/downloads.html   -base system and extensions download page
http://distro.ibiblio.org/tinycorelinux/install.html  -installation instructions
http://tinycorelinux.net/corebook.pdf  -good all in one doc
http://wiki.tinycorelinux.net/wiki:persistence_for_dummies –persistence explained

Linux kernel networking

Your bible for understanding the way the networking works within the Linux kernel should be this page. In this article I would like to list the functionalities available at this level and how they can be configured. This is rather a high level view, I do not intend to rewrite manuals or to supplement the documentation that other wrote for these modules or utilities

Unix systems -history and genealogy

Writing this article reminded me about The history of the middle earth. The J. R Tolkien's fantasy world is far less complicated than the Unix world but they are equally fascinating and vast free for imagination realms and this is where the traveller in this words falls in love with them

Major Unix Systems

A high level map of the major Unix distributions can be seen here:

Why network engineers need to know Linux

Unix is something that I learned long long time ago while Slackware was ruling the world of Linux. At that time I had no idea how much I did not know about it and since then the things went crazy and the Unix Universe enlarged to an unimaginable size.

Becuse today more and more devices are based on Linux I guess it would be bad taste to say you do not know Unix and that goes especially for  Linux. From phones and tablets to robots and routers many many  other things are powered by Linux these days.

This article came out of my frustration with not knowing what exactly I am doing and who I am dealing with when working with various network appliances, especially when it comes to hacking these appliances. Here are just a couple of then that I have been dealing with for the last couple of months:

  • Cisco ASA appliances
  • Alteon Load balancers
  • F5 load balancers
  • OpenVswitch
  • Checkpoint Firewall
  • OpenFlow and Openvswitch
  • Linkys routers usig dd-wrt

The list is quite long and all the above have one thing in common: The Linux Kernel and its network related features. Today’s kernel capabilities have evolved to the point where the Linux kernel is not only a money and time saving solution but it also opens a full range of options when it comes to building network appliances around it

Long story short, my target for these articles is to clarify and put in good order the following:

  • differences between various flavours of Unix/Linux and how they evolved
  • next I will focus on the Linux kernel
  • a list of network appliances that I deal with on a daily basis and what kernel they are based on
  • the kernel networking concepts
  • network emulators and how to use them
  • virtualisation with Linux

I do not intend explore the above to their full extent but just enough to give me the confidence that I know exactly what can be done and what can not be done specific situation.


The Linux Kernel map

I have recently started to develop an interest for virtual networking as this is becoming an important step in a “Cloud” incarnation. Here is just a link for now


I am currently studying the Open vSwitch architecure and features. Next I will continue with a short look at VMware vSwitch and Nexus 1000. The final leg of this virtual trip will be the “virtual appliances” from vendors like F5, Alteon, Checkpoint and so on.

Home Linux networking