Tuesday, March 28, 2006

System setups

Guides to setting up Linux (Ubuntu's my personal choice) with:
* LDAP (openLDAP)
* MailServer (PostFix) & SpamAssassin; IMAP, POP3 & SMTP
* AntiVirus (ClamAV)
* Apache, PHP
* Web-based Administration; ISPMan/WebMin

ISP-Server Setup - Ubuntu 5.10 "Breezy Badger"
Turn your world LDAP-tastic
How to set up a mail server on a GNU / Linux system
Using OpenLDAP
Running ISPMan on Debian 3.0 Full Install Guide

Thursday, March 23, 2006

Security Analogy

In order to better understand the need for security measures on your PC or network, we'll try to draw an analogy between your set-up & a house or complex.
This is only a very rough estimation of what really happens, in order to make more sense of all the technical mumbo-jumbo gobbly-gook

Let's first familiarise ourselves with the terms used:

IT term Analogous term Definition/Description
The Internet The World The public arena in which we all have a place.
The Internet consists of near-countless networks (complexes) loosely connected, but governed by ever-increasing stricter rules & laws to ensure we all behave ourselves.
Like the World, no single entity owns the Internet (though some would like to), but is a collection of everyone in it.
Like the World, the internet is not a bad place, but we all still need to be cautious
Network Complex A collection & grouping of interconnected Computers (Homes).
These nodes are connected by means of the network infrastructure (roads).
This is also sometimes referred to as a 'Network Neighborhood or 'Domain'.
PC or Computer House or Home The space where you reside or operate from.
This represents your space or identity on the web, and for all ends & purposes your character or who you are, in a similar marrer that your desktop might reflect some aspect of your personality, i.e. your desktop wallpaper showing you as a proud parent or your favorite holiday picture
Packet Car A packet represents a 'bundled' unit of data travelling over a network from a source (client) to a destination (server), or visa versa.
A packet is addressed towards a destination, regardless of the route it takes. It might take the most direct route, or hop from network to network in order to reach it's destination
Ports Doors and Windows These are the individual openings on you PC (home) that gives access to the outside world.
All traffic comming in our going out of your PC must go through one or several of thousands of ports.
It's generally advised to keep these ports locked tightly unless it's absolutely necessary, or when being used.
Firewall & Proxy Security Guard & Guardhouse Single point of entry onto the World out there.
The Proxy acts as a bottleneck for all traffic coming in or going out of your 'Neighbourhood'.
To the Internet, the whole 'Complex'/Network needs only to be referenced by a single address, and worry about the specifics later
The Firewall acts as a Security Guard, checking whether it's authorised traffic & not something likely to cause damage.
Just like Guardhouses & Security Guards, the quality of 'service' is only as good as it's education & set-up, but even the best can slip up sometimes; especially if the offending 'agent' is cunning enough.
Browser Vehicle One of the means by which we traverse the Internet.
This enables us to view the Internet in a visual (& sometimes entertaining) manner.
Mail Server Post Office A place where messages (mail) & parcels (attachments) are stored until it gets picked up or delivered.
Unless the Mail Server/Post Office knows what to look for (signatures), anything addressed to you, will be dropped into your mailbox, be it malicious, benign, wanted or unwanted.
Mail Client Postman The agent that picks up mail on your behalf & delivers it to your house.
Just like the 'Post Office', if the 'Mailman' knows what to look for, it can disregard or destroy any malicious packages before it gets delivered to you 'door'.
Internet Service Provider (ISP) Toll-gate The entity we pay a periodical fee to allow us connection to the Internet & the World at large
Just like in the real World these guys sometimes rip us off, but we do have a choice who we can use
I.P-Address Street Address The address by which your location is known to the World out here
This takes the format of 4 sets of numbers ranging from 1 to 255 i.e., but, of course, things are not always as simple
Hacker Nosy Neighbour Someone trying to gain access for the sake of trying
These individuals are not malicious at heart, but their presence is still not welcome
Cracker Burglar These individuals or groups try to break in to steal or do some damage.
In today's information society, information is power.
These people might be after sensitive information, i.e. banking details, company secrets, or any other information they can use to cause further damage; usually at someone else's expense.
AntiVirus, AntiSpyware & Other Security Software/Agents Doctor or Surgeon Just like the real-world counterpart, this is the agent that sees to your PC heath, either through prevention or cure.
Obviously prevention is better than cure, but unlike their real-world counterparts, it's a lot cheaper having Security Software constantly watching over you PC & Network heath, than a real Doctor.