Category: FAQ


This question has not yet appeared in my inbox, although since I have already written an explanation on the meaning of the term “Sniffer” it makes sense to write one about a tool commonly used in conjunction with a “Sniffer”. So here is an explanation on what a “Scanner” is and what it may be used for. Note I am referring to a “Network Scanner” not an optical scanner.

A “Scanner” is a shortened term for “Network Scanner”. The “Network Scanner” is a software program that can be used to passively scan for network broadcasting devices, such as a wireless access point (AP) that could potentially be exploited in order to gain unauthorized access into a system belonging to the network connected to this wireless access point, or perhaps authorized access assuming you have permission from the owner of the network or computer to perform a security audit.

 

By using the term “Passive Scan” I am referring to a scan in what is commonly known to security enthusiasts as a scan in “Monitor Mode”. This means that the wireless device will only capture data packets and broadcast beacons without sending and data packets. Thus making you much less likely to be discovered by the owner of the device or devices that you are collecting data packets from. I would also like to note that in most circumstances collecting wireless packets should be no more illegal than say peering into your neighbour’s lounge room through the front door that he left open. It is in principle no different. Just be sure that if you do choose to pursue the data packets of your surrounding access points that the owner of them is not a security freak or a person with a great lawyer, as this could result in them turning the tables on you and getting you in trouble.

 

Due to the haze between the terms “Sniffer” and “Scanner” personal opinions on each may vary. My preference in network sniffers would be Wireshark and my preference in “Scanner” would be Airodump-ng.

I hope that this has helped you understand the meaning of the term “Scanner” when referring to network security. Have fun testing your network from the outside, perhaps it is not as secure as you may have once thought.

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This question has been rolling into my inbox quite frequently over the past weeks and I have written the answer to the question below.

Please note that this is not a complete guide to the entirety of 802.11 as such, it is more of a basic outline that any intermediate to advanced computer user should be able to understand.

 

Most people with a lack of knowledge related to computing will hear the term “802.11” and immediately think “Wi-Fi”. 802.11 is not necessarily “Wi-Fi” but it is more a term for the standard of such. In short 802.11 is actually more seldom referred to as the 802.11 standard. Meaning that a wireless device should comply with the 802.11 standard in order to be compatible with the majority of wireless devices located around the world. In addition you may like to know that the 802.11 standard in itself defines a link layer wireless protocol, which is managed by a committee known as “IEEE” (a.k.a The Institute of Electrical and Electronics Engineers). As an additional note “Wi-Fi” and “802.11” are similar in principal but are not the same thing.

 

The history of the 802.11 standard is a long one, which I will condense for you.

 

The first 802.11 standard was formally approved in the year 1997. This standard would transmit a maximum of 2Mbps (Mega bits per second).

 

The next standard that was approved and released was in the year of 1999, it was the “802.11b” standard, which was what you could call an add-on to the original “802.11” standard. The “802.11b” standard allowed what seemed then to be a mind-blowing data transfer rate of 11Mbps (11 Mega bits per second).

 

After “802.11b” the “802.11a” protocol was approved and released in 1999, which was oddly enough the same year as the release of its predecessor “802.11b”. This new protocol allowed transmission across the 5Ghz radio band, which in turn reduced interference and crowding across the cliché 2.4Ghz band that still to this day seems to run everything with an antenna. This new protocol allowed a much higher speed due to different transmission techniques and a less congested band, which was a whopping 54Mbps (54 Mega bits per second).

 

Later on in 2003 the IEEE approved and released another new 802.11 protocol standard, which was named 802.11g, which provided the same data transfer rate of 54Mbps (54 Mega bits per second) as the “802.11a”, although it returned to the 2.4Ghz band that was used in most protocol standards prior to the “802.11a” standard. This return to the 2.4Ghz band while offering the same data transfer rate attracted corporations and the general public to adopt the idea and even today it remains one of the most commonly used 802.11 protocols in use.

 

Shortly after the release of the “802.11g” protocol standard, a new protocol was approved and released. This was the “802.11n” protocol standard, which allowed a colossal 100Mbps (100 Mega bits per second) data transfer rate. Although it is still not as widely known and used as the “802.11g” protocol standard.

That is the basic outline of 802.11. I hope that this has answered your question sufficiently.

This question is one that I do get very rarely, although I know that there are a few of you security savvy computer users like myself out there who would love to know exactly what the term “Sniffer” refers to.

A “sniffer” is a software program, which can be either command-line or GUI based. This software program is used to monitor every single data packet that travels through a specific network interface on the computer of which it is running on.

 

For example you decide to run Wireshark (formerly Ethereal) on your computer whilst being connected to your home network. Wireshark is a network sniffer. While you run this software you must then select the network device of which you would like to observe packet data on. Say you were connected to your home network wirelessly using a Broadcom wireless device, which was named “Wlan0” on your computer, you would run Wireshark and select the capture device “Wlan0” and then click the “Start Capture” button at the top of the software window, which would begin capturing all of the data packets sent across your wireless device.

 

Knowing what data packets are flowing across your wireless device that is connected to your home network without internet access is rather pointless, although say you were connected to the internet or you were running a web server on the computer you are running Wireshark on, you would be much more likely to detect an attack and shut down your server to prevent any damage from the attack.

I am sure that this has enlightened you as to the meaning of the term “Sniffer”. You are now one step closer to knowing how to secure your network.

What is Apache?

This piece was written after many requests from our community asking what exactly the term “Apache” means. Read below if you are curious.

The term “Apache” refers to a server software. This software is used to run websites on the internet, which in turn can be accessed from all around the world. Apache software may also be used in the construction of what is known as an “Intranet”.

 

An Intranet is in a way the internet, although it is accessible only to select people. This is commonly used in a corporation such as a bank. An intranet may also be used in a home environment. For example I am running an intranet at my home. The intranet has four devices running from it. There are two desktop computers, a laptop and a Nintendo Wii. These are all interconnected through an MSI router and the Apache server is running on one of the desktop computers. The other desktop computer acts as a network security type system, which will watch my intranet for intrusions and on sight of an intrusion will lockdown my network and prevent all incoming traffic. Upon the lockdown I am notified by a serious of loud beeps from a stereo connected to the network watch system and I can then react on the intrusion as I will be able to probe the computer and in turn receive their IP (internet protocol) address and their current operating system.

 

The above example is a common example of an intranet, although most commercial intranets will be colossal in size in comparison to this. For example a bank or similar corporation may have hundreds or even thousands of computers may be interconnected, potentially over many kilometres. Although the longer the stretch of the intranet can prove more risk in terms of security as it may provide an opening for a cracker or information thief to cut a cable and intercept network traffic.

 

So in general Apache is a server software which can run through command line, also a GUI is available. Apache is also available on practically every operating system. The most commonly used operating system for servers running Apache is a Linux distribution because of its open source nature providing much more opportunity in the way of customization as well as security, speed and reliability.

What are “runlevels” in Ubuntu?

Quite simply a “runlevel” is a state in Ubuntu, which is neither “On” or “Off” but a state in between the two.

A “runlevel” exists in Ubuntu because, unlike other operating systems, Ubuntu allows for different states of operation. These “runlevels” influence which processes are loaded at bootup on a Ubuntu system. These processes being controlled are usually very important processes, such as mounting HDDs on boot or sending output to the input of your monitor.

 

By default all boot processes will be run automatically at boot, although by editing the file that controls the “runlevels” you are able to decide exactly which processes start and in which order.

 

There are several “runlevels” in Ubuntu. They are listed below:

Runlevel Number Runlevel Function
Runlevel 0 This runlevel is also known as “halt” in that it is used to shutdown Ubuntu.
Runlevel 1 This runlevel is unique in that it boots to a shell prompt which will allow a login, although this login must be to the root account only as no other account logins are accepted. This is used for root changes to the system when a graphical interface must not be used, such as installing graphics drivers or updating some system files.
Runlevel 2 This is the regular runlevel for Ubuntu and is used by default.
Runlevel 3 This particular runlevel is not used in Ubuntu, although it is used in an array of other Linux distributions.
Runlevel 4 This particular runlevel is not used in Ubuntu, although it is used in an array of other Linux distributions.
Runlevel 5 This particular runlevel is not used in Ubuntu, although it is used in an array of other Linux distributions.
Runlevel 6 This runlevel is used to restart the Ubuntu system.

I hope that this piece has informed you on the uses of runlevels on Ubuntu, Kubuntu and Xubuntu. Enjoy your newfound Linux knowledge.

This guide is written, keeping in mind a buyer of their first computer, who is running on a tight budget and needs a machine for general use. Read below to find out the basics of looking for a good deal when it comes to buying a computer.

 

Basic home and office computer system

The list below will show you the specifications for a standard computer for use in the home or office for basic tasks such as word processing, powerpoint slideshows and e-mail.

Hard Drive 80GB – 120GB
RAM 1GB – 2GB
WiFi (Wireless Networking) 802.11g/b/n
Ethernet (Cable Networking) 10/100Mbps
Graphics 256MB – 512MB
Processor Clock Speed 2.3GHz – 2.5GHz
USB 1.0/2.0 Ports 2 – 4
Keyboard 1 Required
Mouse 1 Required
Monitor 15inch – 18inch

 

The list above includes what you should be looking for as a minimum for a general, office or home use computer system. The above system should cost you between $700 and $1200, brand new. A similar machine could be purchased in used condition for $300 to $500, depending on how generous the seller is willing to be.

 

Medium performance home and office computer system

The list below will show you the specifications for what would be considered by most as a computer system aimed at home and office use as well as mild gaming and entry-level graphics design. This type of computer I recommend to all first computer buyers, assuming you have a slightly higher budget as it is a much better power-for-money deal depending on whether or not your computer store is offering you a good discount.

Hard Drive 250GB – 360GB
RAM 1GB – 2GB
WiFi (Wireless Networking) 802.11g/b/n
Ethernet (Cable Networking) 10/100Mbps
Graphics 512MB – 1024MB (1GB)
Processor Clock Speed 2.8GHz – 3.2GHz
USB 1.0/2.0 Ports 2 – 6
Keyboard 1 Required
Mouse 1 Required
Monitor 17inch – 21inch

 

The above list depicts the specifications of a very decent machine that will cater for 99% of the general home or office user’s needs. This may seem over the top in the way of power, although the prices of a system like this in brand new condition are actually rather low. The price of a system such as this will usually range between $1200 and $1800. A system similar to this in a used condition will cost you between $500 and $1200. This type of computer system is, without a doubt worth looking for in used condition.

 

Heavy office and gaming computer system

The list of specifications below apply to a heavy office use and a moderate gaming computer. This type of computer system are very well suited to an online gamer or an office user working in the graphic design business or financial business that requires a lot of processing done quickly and reliably.

Hard Drive 500GB – 1TB (1000GB)
RAM 2GB – 4GB
WiFi (Wireless Networking) 802.11g/b/n
Ethernet (Cable Networking) 10/100Mbps
Graphics 1GB – 1.5GB
Processor Clock Speed 3.2GHz – 3.4GHz
USB 1.0/2.0 Ports 2 – 6
Keyboard 1 Required
Mouse 1 Required
Monitor 20inch – 24inch

 

The list of specifications above are that of a heavy office use or basic gaming computer. This particular specification range is aimed at the competent graphic designer or a high demand gamer. This type of system will cost you anywhere from $1900 to $2600 and will provide you with a very fast and responsive computer system for virtually any use.

 

Hardcore gaming and high power corporation computer system

The list below contains the specifications of an extremely powerful gaming computer mainly used by corporations or hardcore gamers. This system is usually very expensive but efficient way to enjoy responsive power.

Hard Drive 1TB – 2TB
RAM 4GB – 8GB
WiFi (Wireless Networking) 802.11g/b/n
Ethernet (Cable Networking) 10/100Mbps
Graphics 1GB – 3GB
Processor Clock Speed 3.5GHz – 3.8GHz
USB 1.0/2.0 Ports 4 – 10
Keyboard 1 Required
Mouse 1 Required
Monitor 20inch – 24inch and up

 

The above listing of specifications is far in excess of requirements of the average household user, although a dream machine for the hardcore gamer or corporation in dire need of heavy computing power. For a corporation, this type of system will be a great deal for power, however for a regular civilian who just loves their gaming, this system may be a little out of reach in the financial sector. This type of system in brand new, off the showroom condition will cost you between $3400 and $10000 depending of course on your selected brand and computer dealer. In used condition this computer will still be rather expensive at between $2000 and $5000.

 

Be sure to read this list before you decide to buy your first computer or even another computer to add to your collection. The key priority is to shop around and if you can’t find a good deal on a computer then a second option is to get a custom built PC, which is commonly thought to be more expensive; however, it is not as in some cases it can cost you 20% of the price as the same commercial machine. As an added plus to getting a computer system custom built to your needs is the fact that you get what you what, how you want and it will suit you perfectly.

 

Once you have purchased your new computer system I would recommend getting your computer secured. To help you do so follow the link below to my Windows security section. If you happen to intend on installing a Linux distribution, it may please you to know that I will soon be releasing a new Linux security guide section to keep you and your family safe from internet predators.

https://chafflube.wordpress.com/category/windows/security/

Enjoy shopping for your new machine and make the most of your computing skill. Enjoy your newfound computer pricing knowledge.

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