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Linux networking

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:


A very detailed view can be seen here:http://www.levenez.com/unix/ (AKA The UNIX History) where you can find a wall long poster(PDF) with all the UNIX distributions that ever existed

A fresh picture of the popularity of each of the Unix distributions can be seen on DistroWatch

The BSD Lineage

Based on a monolithic kernel, it is the parent of the following major Unix distributions:

  • FreeBSDfocused on performance and x86; less open source (ex: HAL modules for device drivers); significant focus on SMP – Nokia IPSO, Juniper Networks, NetApp, Citrix Netscaller, BlueCoat and Apple use this. A complete list of products is here
  • NetBSDportability and clean design, stability efficiency ; clear distinction between machine dependent and machine independent code; compliance with open API
  • OpenBSD -portability, standardization, correctness, proactive security and integrated cryptography. Also used for embedded systems-OpenSSH uses this
  • Debian-GNU/FreeBSD
GNU/Linux distributions

A very detailed GNU/LINUX Time Line poster can be seen here: http://futurist.se/ If you want to see it without visiting that page just click on this icon:.

Here are the major lineages that were of practical interest for me

  • Debian –> Ubuntu
  • Slackware –> Suse (comercial) –> Open Suse
  • RedHat –> RH Enterprise (comercial)–> CentOS (free of proprietary source)
    • Fedora Core –used by Arista Networks
    • Mandrake
  • TinyCore –minimalist Linux (10M)
  • OpenWRT embedded systems—>DDWRT-embedded firewall distribution

The Linux Kernel History

You can read some history here

  • 1991 Publicly announced by Linus Torvalds
  • 1994 v1 is released (i386 , 1.2 supported Alpha, SPARC and MIPS)
  • 1996 v2 is released (SMP –support for multiple processors)
  • 1999 v2.2 (removed global spinlock and added support for new filesystems: NTFS –read only)
  • 2001 v2.4 ISA Plug and Play, USB, PC Cards, Bluetooth, Logical Volume Manager, RAID, ext3
  • 2003 v2.6 various changes (high performance, larger file systems)
  • 2011 v3 is released (no major change, just time based according with Linus)

For a more granular timeline click on the picture –>

The change logs and the sources can be found at http://www.kernel.org/

THE lINUX Kernel Components

For an interactive map for the image below go to http://www.makelinux.net/kernel_map (Credits)

Useful Links

What is next?

Next I will dive into the varius network related kernel modules and utilities and try to clarify for my own benefit and perhaps for your, how each of them is used by various appliances or networking software running on Linux

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