Anonymity of Proxy, Anonymity Of Proxy learn it insideout

Anonymity of Proxy

The exchange of information in Internet is made by the "client - server" model. A client sends a request (what files he needs) and a server sends a reply (required files). For close cooperation (full understanding) between a client and a server the client sends additional information about itself: a version and a name of an operating system, configuration of a browser (including its name and version) etc. This information can be necessary for the server in order to know which web-page should be given (open) to the client. There are different variants of web-pages for different configurations of browsers. However, as long as web-pages do not usually depend on browsers, it makes sense to hide this information from the web-server.

What your browser transmits to a web-server:
a name and a version of an operating system
a name and a version of a browser
configuration of a browser (display resolution, color depth, java / javascript support, ...)
IP-address of a client
Other information

The most important part of such information (and absolutely needless for a web-server) is information about IP-address. Using your IP it is possible to know about you the following:
a country where you are from
a city
your provider?s name and e-mail
your physical address

Information, transmitted by a client to a server is available (accessible) for a server as environment variables. Every information unit is a value of some variable. If any information unit is not transmitted, then corresponding variable will be empty (its value will be undetermined).

These are some environment variables:

REMOTE_ADDR ? IP address of a client

HTTP_VIA ? if it is not empty, then a proxy is used. Value is an address (or several addresses) of a proxy server, this variable is added by a proxy server itself if you use one.

HTTP_X_FORWARDED_FOR ? if it is not empty, then a proxy is used. Value is a real IP address of a client (your IP), this variable is also added by a proxy server if you use one.

HTTP_ACCEPT_LANGUAGE ? what language is used in browser (what language a page should be displayed in)

HTTP_USER_AGENT ? so called "a user?s agent". For all browsers this is Mozilla. Furthermore, browser?s name and version (e.g. MSIE 5.5) and an operating system (e.g. Windows 98) is also mentioned here.

HTTP_HOST ? is a web server?s name

This is a small part of environment variables. In fact there are much more of them (DOCUMENT_ROOT, HTTP_ACCEPT_ENCODING, HTTP_CACHE_CONTROL, HTTP_CONNECTION, SERVER_ADDR, SERVER_SOFTWARE, SERVER_PROTOCOL, ...). Their quantity can depend on settings of both a server and a client.

These are examples of variable values:

REMOTE_ADDR = 194.85.1.1
HTTP_ACCEPT_LANGUAGE = ru
HTTP_USER_AGENT = Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)
HTTP_HOST = www.webserver.ru
HTTP_VIA = 194.85.1.1 (Squid/2.4.STABLE7)
HTTP_X_FORWARDED_FOR = 194.115.5.5

Anonymity at work in Internet is determined by what environment variables "hide" from a web-server.

If a proxy server is not used, then environment variables look in the following way:

REMOTE_ADDR = your IP
HTTP_VIA = not determined
HTTP_X_FORWARDED_FOR = not determined

According to how environment variables "hided" by proxy servers, there are several types of proxies
Transparent Proxies

They do not hide information about your IP address:

REMOTE_ADDR = proxy IP
HTTP_VIA = proxy IP
HTTP_X_FORWARDED_FOR = your IP

The function of such proxy servers is not the improvement of your anonymity in Internet. Their purpose is information cashing, organization of joint access to Internet of several computers, etc.
Anonymous Proxies

All proxy servers, that hide a client?s IP address in any way are called anonymous proxies

Simple Anonymous Proxies

These proxy servers do not hide a fact that a proxy is used, however they replace your IP with its own:
REMOTE_ADDR = proxy IP
HTTP_VIA = proxy IP
HTTP_X_FORWARDED_FOR = proxy IP

These proxies are the most widespread among other anonymous proxy servers.

Distorting Proxies

As well as simple anonymous proxy servers these proxies do not hide the fact that a proxy server is used. However a client?s IP address (your IP address) is replaced with another (arbitrary, random) IP:

REMOTE_ADDR = proxy IP
HTTP_VIA = proxy IP
HTTP_X_FORWARDED_FOR = random IP address
High Anonymity Proxies

These proxy servers are also called "high anonymity proxy". In contrast to other types of anonymity proxy servers they hide a fact of using a proxy:

REMOTE_ADDR = proxy IP
HTTP_VIA = not determined
HTTP_X_FORWARDED_FOR = not determined

That means that values of variables are the same as if proxy is not used, with the exception of one very important thing ? proxy IP is used instead of your IP address.
Summary

Depending on purposes there are transparent and anonymity proxies. However, remember, using proxy servers you hide only your IP from a web-server, but other information (about browser configuration) is accessible!

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Anonymity

Anonymity

I can see you hiding in the shadows over there and so can the logs of all the web sites, FTP servers and other nooks and crannies you visit on the web. The sort of information gathered by these logs and which is available to the webmasters of the sites you visit include the address of the previous site you visited, your IP address, your computer's ID name, your physical location and the name of your ISP along with less personal details such as the operating system you're using and your screen resolution. If someone was snooping through your dustbin to gather information on consumer trends or tracking your every move to see where it is you go everyday you wouldn't be too chuffed would you. Well the web is no different, it's still an invasion of privacy and a threat to security and you don't have to put up with it.

Proxy servers:
Every time you visit a web site, detailed information about your system is automatically provided to the webmaster. This information can be used by hackers to exploit your computer or can be forwarded to the market research departments of consumer corporations who by tracking your activities on the internet are better equipped to direct more relevant spam at you. Your best defence against this is to use what is known as a proxy server, which will hide revealing information from the web sites you visit, allowing you to surf the web anonymously. These work by altering the way in which your browser retrieves web pages or connects to remote servers. With a proxy server set up, whenever you 'ask' IE or Netscape to look at a web page, the request is first sent through an external server which is completely independent of your ISP's servers. This third party server then does the requesting on your behalf so that it appears that the request came from them rather than you and your real IP address is never disclosed to the sites you visit. There is nothing to download and the whole process takes less than a minute.

There are two different ways to use proxy servers and both have their advantages and disadvantages. The first method is to use a web based service. What this involves is visiting the proxy's home page each time you want to browse a web site anonymously. The core component of such a system is the dialog box where you enter the address of the web site you want to visit. Each time you enter the URL of the site you want to browse via the proxy into this box, your personal information, IP address and so on is first encrypted before being sent to the site allowing you to maintain your anonymity. Two of the best examples of this type of web based proxy service are Code:
hxxp://www.rewebber.com/
and hxxp://www.anonymizer.com/.

Obviously one disadvantage of using a web based service like Rewebber or Anonymizer, however, is that you have to visit the proxies home page each time you want to surf anonymously. You could choose to select this page as your default home page, but it's still quite awkward if you're forever site hopping at the speed of light. The second main 'con' is that you often have to put up with extra adverts on the pages you visit. These are automatically inserted into the pages by the proxy - they have to pay for service somehow. More sophisticated and convenient solutions are also on offer yet they come with a price tag.

The second method you can use to protect your privacy via a proxy server involves adjusting the settings of your web browser so that you can surf anonymously without having to visit the home page of your proxy each time. To do this you will first need to know the name of your proxy server and the port number it uses. This information can be gleaned from either a public proxy server list or the FAQ referring to a private subscription based service. Once you have the name of the proxy server you wish to use, select 'Internet Options' from the 'Tools' menu of your browser. Now select 'Connections' followed by 'Settings' and tick the 'use a proxy server' check box. To finish the job all you have to do now is enter the name of the server in the 'address' box, the port which it uses in the 'port' box and go forth and surf anonymously.

Free, manual proxy servers as advertised on anonymity sites, if you can find one at all, are likely to be highly oversubscribed, and as a result the speed at which they retrieve web pages can deteriorate. In which case you can go in pursuit of a public proxy server list and select an alternative from it, which can then be set up manually. To locate such a list you can investigate sites such as Code:
hxxp://www.proxys4all.com/

however, this method isn't problem free either, so before you get too carried away and go jumping on the anonymity bandwagon there are a few things you should be aware of. It's very easy to use proxies to protect your privacy, but often the disadvantages of using them far out weigh the benefits. You see, the problem is that, like the proxy servers provided Rewebber et al, free, public proxies are nearly all over subscribed and so they can slow down web browsing considerably. Digging out fast reliable proxy servers is an art form in itself and is a skill which takes considerable practice. You could find a list of public proxy servers and then experiment with each one until you find one that runs at a reasonable speed, but this can be very time consuming and frustrating. Instead, your search would be much more efficient if you got a dedicated program to carry out this task for you. There are literally dozens of proxy seeking programs around which can do just that, and many of them are available as freeware. What these do is scan the internet for public proxy servers. These servers are then tested for speed and anonymity (not all of them are truly anonymous, even if they claim to be!) and once you find one which suits your requirements you can select it as your default proxy with the click of a button.

One of the most significant advantages of using an automated tool to locate proxy servers is that you do not have to keep editing your proxy settings manually each time you wish to try out a new one. Instead, what you do is enter 'localhost' or '127.0.0.1' into the 'address' box and '8088' into the 'port' box of your browser's proxy settings menu and then forget about it. All future proxy switching is then orchestrated from within your proxy seeking software, which subsequently relays the information to your browser or whatever type of application you are attempting to make anonymous. For those of you who are curious 'localhost' and the IP address '127.0.0.1' are the names by which every computer on the internet refers to itself.
Here's a good selection of links, which should help you to get started - Code:
hxxp://www.a4proxy.com/ Anonymity 4 Proxy
hxxp://www.helgasoft.com/hiproxy/ Hi Proxy
hxxp://www.proxy-verifier.com/ Proxy Verifier
hxxp://www.photono-software.de/ Stealther.

You may find that even when using these programs you have difficulty finding good proxy servers. It is for this reason that many people choose only to use proxy servers temporarily whilst doing something which may land them in trouble with their ISP, or in a worst case scenario with the law. The most obvious example of a situation in which you would want to cover your tracks is when scanning for public FTP servers and subsequently uploading to them. Most other net activities are unlikely to incur serious consequences so under these circumstances you can safely surf the web without a proxy. If you're really serious about protecting your privacy, however, your best bet is probably to invest in a dedicated, stable proxy such as the ones offered by Code:
hxxp://www.ultimate-anonymity.com/ Ultimate Anonymity


These aren't free, but may be worth the expense if you aren't keen on continuously switching proxy servers.

Before splashing out though it may be worth checking if your current ISP has a proxy server of its own which you can use. These aren't there to help you to commit cyber crimes and get away with it, they actually have a legitimate purpose as well - otherwise they wouldn't exist. You see, proxy servers were originally designed to help speed up web page loading times. Proxy servers contain a cache of all the web pages which have been requested via the browsers of the people using the proxy. When someone surfs the web using a proxy, the proxy first checks to see if it already has a copy of the web page stored in its cache. If this version of the page is bang up to date, it is sent to your computer and appears in your browser. If the page found in the cache of the proxy server is older than the one stored on the server hosting the page, a new request to the web server is made and the page is updated in the cache of the proxy before being sent to you. Because these servers use very fast internet connections they can retrieve web pages at much greater speeds than you can via your modest home setup. If these servers are located physically nearer to your home than the web host servers you wish to retrieve web pages from, the speed at which you browse the web will be accelerated.


Anonymity - Cookies
One last important point you need to be aware of before jumping in with both feet is that different programs have to be setup in different ways before being able to make external connections via a proxy server. For example, you can surf the web anonymously by modifying the settings in Internet Explorer or Netscape Navigator as explained earlier in this tutorial, but this will only affect your browser. If you then used Flash FXP to copy a batch of 0-day releases from one FTP server to another, this isn't going to protect you in the slightest. What you have to do is enter the name of the proxy server into each application you wish to make anonymous before making any external connections. This can usually be done by browsing through the preferences of your program to see if there is a 'use proxy server' option available. If there is, make sure you use it!


Cookies:
You have little to fear from the edible variety, but the digital ones can be a major threat to your security and privacy. A cookie is a tiny text file (usually less than 1kb in size), which is created and stored on your hard drive whenever you visit a dynamic (or an interactive if you like) web site. These are used to log your personal details so that you can access members only areas of web sites without having to type in a password every time, or to retain your customised settings so that they are available the next time you visit. If you're using a shared computer, anyone who visits the same site that you have previously logged in to can access your accounts. This is particularly worrying if you have entered your credit card details into a form on an e-commerce site. If your browser is set to automatically fill in these details whenever you
return to a previously visited site, this information could be clearly visible - you don't need me to explain the problems this could entail.

The solution to this problem is to delete any cookies which contain sensitive data once you have completed your transactions. Your cookies will be stored in a different place depending on which operating system you are using so you will have to use your detective skills to find them. As an example, in Windows XP they are located in your 'c:\Documents and Settings\Kylie Minogue\Cookies' directory (that is if your name is Kylie Minogue. Mine isn't in case you're wondering!). If you look in this directory, in some cases it is easy to identify which cookie is associated with which web site, but in other cases it's not so obvious. The cookie which was created when you visited Yahoo.com to check your email may be called kylie minogue@yahoo.txt for example. Unfortunately some cookies refer to the IP address of the site you visited and so look more like kylie minogue@145.147.25.21. These cookies can be selectively deleted one at a time if it's obvious which ones are causing a threat to your security, or you can just wipe out the whole lot in one fell swoop and have them recreated as and when they are required. However, if
you're really struggling to find your cookie jar, you could delete your cookies via your browser's tool bar instead. In Internet Explorer this can be done through the 'Tools' > 'Internet Options' menu items.

If all this sounds like too much hassle, you can always find a labour saving program which will be happy to take the job off your hands. These 'cookie crunching' programs allow you to be more selective when editing, viewing and deleting cookies from your system, and some of them will even prevent cookies from being created in the first place. Yes, I know you're hungry for links so I won't deprive you. Have a look here - Code:
hxxp://www.rbaworld.com/Programs/CookieCruncher/ Cookie
Cruncher
hxxp://www.thelimitsoft.com/ Cookie Crusher
hxxp://www.angove.com/ Cookie Killer
hxxp://www.kburra.com/ Cookie Pal
and
hxxp://www.cookiecentral.com/ Cookie Web Kit.

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Explanation about bandwidth

This is well written explanation about bandwidth, very useful info.



BandWidth Explained

Most hosting companies offer a variety of bandwidth options in their plans. So exactly what is bandwidth as it relates to web hosting? Put simply, bandwidth is the amount of traffic that is allowed to occur between your web site and the rest of the internet. The amount of bandwidth a hosting company can provide is determined by their network connections, both internal to their data center and external to the public internet.


Network Connectivity

The internet, in the most simplest of terms, is a group of millions of computers connected by networks. These connections within the internet can be large or small depending upon the cabling and equipment that is used at a particular internet location. It is the size of each network connection that determines how much bandwidth is available. For example, if you use a DSL connection to connect to the internet, you have 1.54 Mega bits (Mb) of bandwidth. Bandwidth therefore is measured in bits (a single 0 or 1). Bits are grouped in bytes which form words, text, and other information that is transferred between your computer and the internet.

If you have a DSL connection to the internet, you have dedicated bandwidth between your computer and your internet provider. But your internet provider may have thousands of DSL connections to their location. All of these connection aggregate at your internet provider who then has their own dedicated connection to the internet (or multiple connections) which is much larger than your single connection. They must have enough bandwidth to serve your computing needs as well as all of their other customers. So while you have a 1.54Mb connection to your internet provider, your internet provider may have a 255Mb connection to the internet so it can accommodate your needs and up to 166 other users (255/1.54).


Traffic

A very simple analogy to use to understand bandwidth and traffic is to think of highways and cars. Bandwidth is the number of lanes on the highway and traffic is the number of cars on the highway. If you are the only car on a highway, you can travel very quickly. If you are stuck in the middle of rush hour, you may travel very slowly since all of the lanes are being used up.

Traffic is simply the number of bits that are transferred on network connections. It is easiest to understand traffic using examples. One Gigabyte is 2 to the 30th power (1,073,741,824) bytes. One gigabyte is equal to 1,024 megabytes. To put this in perspective, it takes one byte to store one character. Imagine 100 file cabinets in a building, each of these cabinets holds 1000 folders. Each folder has 100 papers. Each paper contains 100 characters - A GB is all the characters in the building. An MP3 song is about 4MB, the same song in wav format is about 40MB, a full length movie can be 800MB to 1000MB (1000MB = 1GB).

If you were to transfer this MP3 song from a web site to your computer, you would create 4MB of traffic between the web site you are downloading from and your computer. Depending upon the network connection between the web site and the internet, the transfer may occur very quickly, or it could take time if other people are also downloading files at the same time. If, for example, the web site you download from has a 10MB connection to the internet, and you are the only person accessing that web site to download your MP3, your 4MB file will be the only traffic on that web site. However, if three people are all downloading that same MP at the same time, 12MB (3 x 4MB) of traffic has been created. Because in this example, the host only has 10MB of bandwidth, someone will have to wait. The network equipment at the hosting company will cycle through each person downloading the file and transfer a small portion at a time so each person's file transfer can take place, but the transfer for everyone downloading the file will be slower. If 100 people all came to the site and downloaded the MP3 at the same time, the transfers would be extremely slow. If the host wanted to decrease the time it took to download files simultaneously, it could increase the bandwidth of their internet connection (at a cost due to upgrading equipment).


Hosting Bandwidth

In the example above, we discussed traffic in terms of downloading an MP3 file. However, each time you visit a web site, you are creating traffic, because in order to view that web page on your computer, the web page is first downloaded to your computer (between the web site and you) which is then displayed using your browser software (Internet Explorer, Netscape, etc.) . The page itself is simply a file that creates traffic just like the MP3 file in the example above (however, a web page is usually much smaller than a music file).

A web page may be very small or large depending upon the amount of text and the number and quality of images integrated within the web page. For example, the home page for CNN.com is about 200KB (200 Kilobytes = 200,000 bytes = 1,600,000 bits). This is typically large for a web page. In comparison, Yahoo's home page is about 70KB.


How Much Bandwidth Is Enough?

It depends (don't you hate that answer). But in truth, it does. Since bandwidth is a significant determinant of hosting plan prices, you should take time to determine just how much is right for you. Almost all hosting plans have bandwidth requirements measured in months, so you need to estimate the amount of bandwidth that will be required by your site on a monthly basis

If you do not intend to provide file download capability from your site, the formula for calculating bandwidth is fairly straightforward:

Average Daily Visitors x Average Page Views x Average Page Size x 31 x Fudge Factor

If you intend to allow people to download files from your site, your bandwidth calculation should be:

[(Average Daily Visitors x Average Page Views x Average Page Size) +
(Average Daily File Downloads x Average File Size)] x 31 x Fudge Factor

Let us examine each item in the formula:

Average Daily Visitors - The number of people you expect to visit your site, on average, each day. Depending upon how you market your site, this number could be from 1 to 1,000,000.

Average Page Views - On average, the number of web pages you expect a person to view. If you have 50 web pages in your web site, an average person may only view 5 of those pages each time they visit.

Average Page Size - The average size of your web pages, in Kilobytes (KB). If you have already designed your site, you can calculate this directly.

Average Daily File Downloads - The number of downloads you expect to occur on your site. This is a function of the numbers of visitors and how many times a visitor downloads a file, on average, each day.

Average File Size - Average file size of files that are downloadable from your site. Similar to your web pages, if you already know which files can be downloaded, you can calculate this directly.

Fudge Factor - A number greater than 1. Using 1.5 would be safe, which assumes that your estimate is off by 50%. However, if you were very unsure, you could use 2 or 3 to ensure that your bandwidth requirements are more than met.

Usually, hosting plans offer bandwidth in terms of Gigabytes (GB) per month. This is why our formula takes daily averages and multiplies them by 31.


Summary

Most personal or small business sites will not need more than 1GB of bandwidth per month. If you have a web site that is composed of static web pages and you expect little traffic to your site on a daily basis, go with a low bandwidth plan. If you go over the amount of bandwidth allocated in your plan, your hosting company could charge you over usage fees, so if you think the traffic to your site will be significant, you may want to go through the calculations above to estimate the amount of bandwidth required in a hosting plan.

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Auto End Tasks to Enable a Proper Shutdown, Win XP Tweak

 Auto End Tasks to Enable a Proper Shutdown

This reg file automatically ends tasks and timeouts that prevent programs from shutting down and clears the Paging File on Exit.

1. Copy the following (everything in the box) into notepad.


QUOTE
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"ClearPageFileAtShutdown"=dword:00000001

[HKEY_USERS\.DEFAULT\Control Panel\Desktop]
"AutoEndTasks"="1"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control]
"WaitToKillServiceTimeout"="1000"


2. Save the file as shutdown.reg
3. Double click the file to import into your registry.

NOTE: If your anti-virus software warns you of a "malicious" script, this is normal if you have "Script Safe" or similar technology enabled.

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Anti Leech Hacking Tutorial

I was just asking to know if there is some audiance before
here is my methode
for hacking anti leech
we gona use a soft calde proxo mitron
proxomitron is an anti bull script web proxy it' works buy applying some rules to elliuminte pop up and many other thing but for our cas we need to desactive all this filtring first goto
w-w.proxomitron.info
download a copy of the soft
then you need to unselect all the option of the soft
and clik on log window
no go to a anti leech web site
use the plug in and not netpumper
in the plugin
add a proxy
you must put this proxy adress
127.0.0.1 8080 for http
the same for ftp
now select the file to download a click download
watch in proximitron log winodws you will see many internal forwarding
if the file are located in a ftp server
proximitron dont handel them
and you will find an error
in a ftp adress
if it's a http adress
you will find some thing like
get /blablalma/bla/file
site tr.com
and you have foudn the adress
it' tr.com/blabla/file

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Anonymity of Proxy, Anonymity Of Proxy learn it insideout

Anonymity of Proxy

The exchange of information in Internet is made by the "client - server" model. A client sends a request (what files he needs) and a server sends a reply (required files). For close cooperation (full understanding) between a client and a server the client sends additional information about itself: a version and a name of an operating system, configuration of a browser (including its name and version) etc. This information can be necessary for the server in order to know which web-page should be given (open) to the client. There are different variants of web-pages for different configurations of browsers. However, as long as web-pages do not usually depend on browsers, it makes sense to hide this information from the web-server.

What your browser transmits to a web-server:
a name and a version of an operating system
a name and a version of a browser
configuration of a browser (display resolution, color depth, java / javascript support, ...)
IP-address of a client
Other information

The most important part of such information (and absolutely needless for a web-server) is information about IP-address. Using your IP it is possible to know about you the following:
a country where you are from
a city
your provider?s name and e-mail
your physical address

Information, transmitted by a client to a server is available (accessible) for a server as environment variables. Every information unit is a value of some variable. If any information unit is not transmitted, then corresponding variable will be empty (its value will be undetermined).

These are some environment variables:

REMOTE_ADDR ? IP address of a client

HTTP_VIA ? if it is not empty, then a proxy is used. Value is an address (or several addresses) of a proxy server, this variable is added by a proxy server itself if you use one.

HTTP_X_FORWARDED_FOR ? if it is not empty, then a proxy is used. Value is a real IP address of a client (your IP), this variable is also added by a proxy server if you use one.

HTTP_ACCEPT_LANGUAGE ? what language is used in browser (what language a page should be displayed in)

HTTP_USER_AGENT ? so called "a user?s agent". For all browsers this is Mozilla. Furthermore, browser?s name and version (e.g. MSIE 5.5) and an operating system (e.g. Windows 98) is also mentioned here.

HTTP_HOST ? is a web server?s name

This is a small part of environment variables. In fact there are much more of them (DOCUMENT_ROOT, HTTP_ACCEPT_ENCODING, HTTP_CACHE_CONTROL, HTTP_CONNECTION, SERVER_ADDR, SERVER_SOFTWARE, SERVER_PROTOCOL, ...). Their quantity can depend on settings of both a server and a client.

These are examples of variable values:

REMOTE_ADDR = 194.85.1.1
HTTP_ACCEPT_LANGUAGE = ru
HTTP_USER_AGENT = Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)
HTTP_HOST = www.webserver.ru
HTTP_VIA = 194.85.1.1 (Squid/2.4.STABLE7)
HTTP_X_FORWARDED_FOR = 194.115.5.5

Anonymity at work in Internet is determined by what environment variables "hide" from a web-server.

If a proxy server is not used, then environment variables look in the following way:

REMOTE_ADDR = your IP
HTTP_VIA = not determined
HTTP_X_FORWARDED_FOR = not determined

According to how environment variables "hided" by proxy servers, there are several types of proxies
Transparent Proxies

They do not hide information about your IP address:

REMOTE_ADDR = proxy IP
HTTP_VIA = proxy IP
HTTP_X_FORWARDED_FOR = your IP

The function of such proxy servers is not the improvement of your anonymity in Internet. Their purpose is information cashing, organization of joint access to Internet of several computers, etc.
Anonymous Proxies

All proxy servers, that hide a client?s IP address in any way are called anonymous proxies

Simple Anonymous Proxies

These proxy servers do not hide a fact that a proxy is used, however they replace your IP with its own:
REMOTE_ADDR = proxy IP
HTTP_VIA = proxy IP
HTTP_X_FORWARDED_FOR = proxy IP

These proxies are the most widespread among other anonymous proxy servers.

Distorting Proxies

As well as simple anonymous proxy servers these proxies do not hide the fact that a proxy server is used. However a client?s IP address (your IP address) is replaced with another (arbitrary, random) IP:

REMOTE_ADDR = proxy IP
HTTP_VIA = proxy IP
HTTP_X_FORWARDED_FOR = random IP address
High Anonymity Proxies

These proxy servers are also called "high anonymity proxy". In contrast to other types of anonymity proxy servers they hide a fact of using a proxy:

REMOTE_ADDR = proxy IP
HTTP_VIA = not determined
HTTP_X_FORWARDED_FOR = not determined

That means that values of variables are the same as if proxy is not used, with the exception of one very important thing ? proxy IP is used instead of your IP address.
Summary

Depending on purposes there are transparent and anonymity proxies. However, remember, using proxy servers you hide only your IP from a web-server, but other information (about browser configuration) is accessible!

Read more »

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All about FTP

 Setting Up A Ftp:


Well, since many of us have always wondered this, here it is. Long and drawn out. Also, before attempting this, realize one thing; You will have to give up your time, effort, bandwidth, and security to have a quality ftp server.
That being said, here it goes. First of all, find out if your IP (Internet Protocol) is static (not changing) or dynamic (changes everytime you log on). To do this, first consider the fact if you have a dial up modem. If you do, chances are about 999 999 out of 1 000 000 that your IP is dynamic. To make it static, just go to a place like h*tp://www.myftp.org/ to register for a static ip address.

You'll then need to get your IP. This can be done by doing this:
Going to Start -> Run -> winipcfg or www.ask.com and asking 'What is my IP?'

After doing so, you'll need to download an FTP server client. Personally, I'd recommend G6 FTP Server, Serv-U FTPor Bullitproof v2.15 all three of which are extremely reliable, and the norm of the ftp world.
You can download them on this site: h*tp://www.liaokai.com/softw_en/d_index.htm

First, you'll have to set up your ftp. For this guide, I will use step-by-step instructions for G6. First, you'll have to go into 'Setup -> General'. From here, type in your port # (default is 21). I recommend something unique, or something a bit larger (ex: 3069). If you want to, check the number of max users (this sets the amount of simultaneous maximum users on your server at once performing actions - The more on at once, the slower the connection and vice versa).

The below options are then chooseable:
-Launch with windows
-Activate FTP Server on Start-up
-Put into tray on startup
-Allow multiple instances
-Show "Loading..." status at startup
-Scan drive(s) at startup
-Confirm exit

You can do what you want with these, as they are pretty self explanatory. The scan drive feature is nice, as is the 2nd and the last option. From here, click the 'options' text on the left column.

To protect your server, you should check 'login check' and 'password check', 'Show relative path (a must!)', and any other options you feel you'll need. After doing so, click the 'advanced' text in the left column. You should then leave the buffer size on the default (unless of course you know what you're doing ), and then allow the type of ftp you want.

Uploading and downloading is usually good, but it's up to you if you want to allow uploads and/or downloads. For the server priority, that will determine how much conventional memory will be used and how much 'effort' will go into making your server run smoothly.

Anti-hammering is also good, as it prevents people from slowing down your speed. From here, click 'Log Options' from the left column. If you would like to see and record every single command and clutter up your screen, leave the defaults.

But, if you would like to see what is going on with the lowest possible space taken, click 'Screen' in the top column. You should then check off 'Log successful logins', and all of the options in the client directry, except 'Log directory changes'. After doing so, click 'Ok' in the bottom left corner.

You will then have to go into 'Setup -> User Accounts' (or ctrl & u). From here, you should click on the right most column, and right click. Choose 'Add', and choose the username(s) you would like people to have access to.

After giving a name (ex: themoonlanding), you will have to give them a set password in the bottom column (ex: wasfaked). For the 'Home IP' directory, (if you registered with a static server, check 'All IP Homes'. If your IP is static by default, choose your IP from the list. You will then have to right click in the very center column, and choose 'Add'.

From here, you will have to set the directory you want the people to have access to. After choosing the directory, I suggest you choose the options 'Read', 'List', and 'Subdirs', unless of course you know what you're doing . After doing so, make an 'upload' folder in the directory, and choose to 'add' this folder seperately to the center column. Choose 'write', 'append', 'make', 'list', and 'subdirs'. This will allow them to upload only to specific folders (your upload folder).

Now click on 'Miscellaneous' from the left column. Choose 'enable account', your time-out (how long it takes for people to remain idle before you automatically kick them off), the maximum number of users for this name, the maximum number of connections allowed simultaneously for one ip address, show relative path (a must!), and any other things at the bottom you'd like to have. Now click 'Ok'.
**Requested**


From this main menu, click the little boxing glove icon in the top corner, and right click and unchoose the hit-o-meter for both uploads and downloads (with this you can monitor IP activity). Now click the lightning bolt, and your server is now up and running.

Post your ftp info, like this:

213.10.93.141 (or something else, such as: 'f*p://example.getmyip.com')

User: *** (The username of the client)

Pass: *** (The password)

Port: *** (The port number you chose)

So make a FTP and join the FTP section


Listing The Contents Of A Ftp:

Listing the content of a FTP is very simple.
You will need FTP Content Maker, which can be downloaded from here:
ht*p://www.etplanet.com/download/application/FTP%20Content%20Maker%201.02.zip

1. Put in the IP of the server. Do not put "ftp://" or a "/" because it will not work if you do so.
2. Put in the port. If the port is the default number, 21, you do not have to enter it.
3. Put in the username and password in the appropriate fields. If the login is anonymous, you do not have to enter it.
4. If you want to list a specific directory of the FTP, place it in the directory field. Otherwise, do not enter anything in the directory field.
5. Click "Take the List!"
6. After the list has been taken, click the UBB output tab, and copy and paste to wherever you want it.


If FTP Content Maker is not working, it is probably because the server does not utilize Serv-U Software.

If you get this error message:
StatusCode = 550
LastResponse was : 'Unable to open local file test-ftp'
Error = 550 (Unable to open local file test-ftp)
Error = Unable to open local file test-ftp = 550
Close and restart FTP Content Maker, then try again.




error messages:

110 Restart marker reply. In this case, the text is exact and not left to the particular implementation; it must read: MARK yyyy = mmmm Where yyyy is User-process data stream marker, and mmmm server's equivalent marker (note the spaces between markers and "=").
120 Service ready in nnn minutes.
125 Data connection already open; transfer starting.
150 File status okay; about to open data connection.
200 Command okay.
202 Command not implemented, superfluous at this site.
211 System status, or system help reply.
212 Directory status.
213 File status.
214 Help message. On how to use the server or the meaning of a particular non-standard command. This reply is useful only to the human user.
215 NAME system type. Where NAME is an official system name from the list in the Assigned Numbers document.
220 Service ready for new user.
221 Service closing control connection. Logged out if appropriate.
225 Data connection open; no transfer in progress.
226 Closing data connection. Requested file action successful (for example, file transfer or file abort).
227 Entering Passive Mode (h1,h2,h3,h4,p1,p2).
230 User logged in, proceed.
250 Requested file action okay, completed.
257 "PATHNAME" created.
331 User name okay, need password.
332 Need account for login.
350 Requested file action pending further information.
421 Too many users logged to the same account
425 Can't open data connection.
426 Connection closed; transfer aborted.
450 Requested file action not taken. File unavailable (e.g., file busy).
451 Requested action aborted: local error in processing.
452 Requested action not taken. Insufficient storage space in system.
500 Syntax error, command unrecognized. This may include errors such as command line too long.
501 Syntax error in parameters or arguments.
502 Command not implemented.
503 Bad sequence of commands.
504 Command not implemented for that parameter.
530 Not logged in.
532 Need account for storing files.
550 Requested action not taken. File unavailable (e.g., file not found, no access).
551 Requested action aborted: page type unknown.
552 Requested file action aborted. Exceeded storage allocation (for current directory or dataset).
553 Requested action not taken. File name not allowed.


 Active FTP vs. Passive FTP, a Definitive Explanation

Introduction
One of the most commonly seen questions when dealing with firewalls and other Internet connectivity issues is the difference between active and passive FTP and how best to support either or both of them. Hopefully the following text will help to clear up some of the confusion over how to support FTP in a firewalled environment.

This may not be the definitive explanation, as the title claims, however, I've heard enough good feedback and seen this document linked in enough places to know that quite a few people have found it to be useful. I am always looking for ways to improve things though, and if you find something that is not quite clear or needs more explanation, please let me know! Recent additions to this document include the examples of both active and passive command line FTP sessions. These session examples should help make things a bit clearer. They also provide a nice picture into what goes on behind the scenes during an FTP session. Now, on to the information...



The Basics
FTP is a TCP based service exclusively. There is no UDP component to FTP. FTP is an unusual service in that it utilizes two ports, a 'data' port and a 'command' port (also known as the control port). Traditionally these are port 21 for the command port and port 20 for the data port. The confusion begins however, when we find that depending on the mode, the data port is not always on port 20.



Active FTP
In active mode FTP the client connects from a random unprivileged port (N > 1024) to the FTP server's command port, port 21. Then, the client starts listening to port N+1 and sends the FTP command PORT N+1 to the FTP server. The server will then connect back to the client's specified data port from its local data port, which is port 20.

From the server-side firewall's standpoint, to support active mode FTP the following communication channels need to be opened:

FTP server's port 21 from anywhere (Client initiates connection)
FTP server's port 21 to ports > 1024 (Server responds to client's control port)
FTP server's port 20 to ports > 1024 (Server initiates data connection to client's data port)
FTP server's port 20 from ports > 1024 (Client sends ACKs to server's data port)


In step 1, the client's command port contacts the server's command port and sends the command PORT 1027. The server then sends an ACK back to the client's command port in step 2. In step 3 the server initiates a connection on its local data port to the data port the client specified earlier. Finally, the client sends an ACK back as shown in step 4.

The main problem with active mode FTP actually falls on the client side. The FTP client doesn't make the actual connection to the data port of the server--it simply tells the server what port it is listening on and the server connects back to the specified port on the client. From the client side firewall this appears to be an outside system initiating a connection to an internal client--something that is usually blocked.



Active FTP Example
Below is an actual example of an active FTP session. The only things that have been changed are the server names, IP addresses, and user names. In this example an FTP session is initiated from testbox1.slacksite.com (192.168.150.80), a linux box running the standard FTP command line client, to testbox2.slacksite.com (192.168.150.90), a linux box running ProFTPd 1.2.2RC2. The debugging (-d) flag is used with the FTP client to show what is going on behind the scenes. Everything in red is the debugging output which shows the actual FTP commands being sent to the server and the responses generated from those commands. Normal server output is shown in black, and user input is in bold.

There are a few interesting things to consider about this dialog. Notice that when the PORT command is issued, it specifies a port on the client (192.168.150.80) system, rather than the server. We will see the opposite behavior when we use passive FTP. While we are on the subject, a quick note about the format of the PORT command. As you can see in the example below it is formatted as a series of six numbers separated by commas. The first four octets are the IP address while the second two octets comprise the port that will be used for the data connection. To find the actual port multiply the fifth octet by 256 and then add the sixth octet to the total. Thus in the example below the port number is ( (14*256) + 178), or 3762. A quick check with netstat should confirm this information.

testbox1: {/home/p-t/slacker/public_html} % ftp -d testbox2
Connected to testbox2.slacksite.com.
220 testbox2.slacksite.com FTP server ready.
Name (testbox2:slacker): slacker
---> USER slacker
331 Password required for slacker.
Password: TmpPass
---> PASS XXXX
230 User slacker logged in.
---> SYST
215 UNIX Type: L8
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls
ftp: setsockopt (ignored): Permission denied
---> PORT 192,168,150,80,14,178
200 PORT command successful.
---> LIST
150 Opening ASCII mode data connection for file list.
drwx------ 3 slacker users 104 Jul 27 01:45 public_html
226 Transfer complete.
ftp> quit
---> QUIT
221 Goodbye.


Passive FTP
In order to resolve the issue of the server initiating the connection to the client a different method for FTP connections was developed. This was known as passive mode, or PASV, after the command used by the client to tell the server it is in passive mode.

In passive mode FTP the client initiates both connections to the server, solving the problem of firewalls filtering the incoming data port connection to the client from the server. When opening an FTP connection, the client opens two random unprivileged ports locally (N > 1024 and N+1). The first port contacts the server on port 21, but instead of then issuing a PORT command and allowing the server to connect back to its data port, the client will issue the PASV command. The result of this is that the server then opens a random unprivileged port (P > 1024) and sends the PORT P command back to the client. The client then initiates the connection from port N+1 to port P on the server to transfer data.

From the server-side firewall's standpoint, to support passive mode FTP the following communication channels need to be opened:

FTP server's port 21 from anywhere (Client initiates connection)
FTP server's port 21 to ports > 1024 (Server responds to client's control port)
FTP server's ports > 1024 from anywhere (Client initiates data connection to random port specified by server)
FTP server's ports > 1024 to remote ports > 1024 (Server sends ACKs (and data) to client's data port)



In step 1, the client contacts the server on the command port and issues the PASV command. The server then replies in step 2 with PORT 2024, telling the client which port it is listening to for the data connection. In step 3 the client then initiates the data connection from its data port to the specified server data port. Finally, the server sends back an ACK in step 4 to the client's data port.

While passive mode FTP solves many of the problems from the client side, it opens up a whole range of problems on the server side. The biggest issue is the need to allow any remote connection to high numbered ports on the server. Fortunately, many FTP daemons, including the popular WU-FTPD allow the administrator to specify a range of ports which the FTP server will use. See Appendix 1 for more information.

The second issue involves supporting and troubleshooting clients which do (or do not) support passive mode. As an example, the command line FTP utility provided with Solaris does not support passive mode, necessitating a third-party FTP client, such as ncftp.

With the massive popularity of the World Wide Web, many people prefer to use their web browser as an FTP client. Most browsers only support passive mode when accessing ftp:// URLs. This can either be good or bad depending on what the servers and firewalls are configured to support.



Passive FTP Example
Below is an actual example of a passive FTP session. The only things that have been changed are the server names, IP addresses, and user names. In this example an FTP session is initiated from testbox1.slacksite.com (192.168.150.80), a linux box running the standard FTP command line client, to testbox2.slacksite.com (192.168.150.90), a linux box running ProFTPd 1.2.2RC2. The debugging (-d) flag is used with the FTP client to show what is going on behind the scenes. Everything in red is the debugging output which shows the actual FTP commands being sent to the server and the responses generated from those commands. Normal server output is shown in black, and user input is in bold.

Notice the difference in the PORT command in this example as opposed to the active FTP example. Here, we see a port being opened on the server (192.168.150.90) system, rather than the client. See the discussion about the format of the PORT command above, in the Active FTP Example section.

testbox1: {/home/p-t/slacker/public_html} % ftp -d testbox2
Connected to testbox2.slacksite.com.
220 testbox2.slacksite.com FTP server ready.
Name (testbox2:slacker): slacker
---> USER slacker
331 Password required for slacker.
Password: TmpPass
---> PASS XXXX
230 User slacker logged in.
---> SYST
215 UNIX Type: L8
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> passive
Passive mode on.
ftp> ls
ftp: setsockopt (ignored): Permission denied
---> PASV
227 Entering Passive Mode (192,168,150,90,195,149).
---> LIST
150 Opening ASCII mode data connection for file list
drwx------ 3 slacker users 104 Jul 27 01:45 public_html
226 Transfer complete.
ftp> quit
---> QUIT
221 Goodbye.


Summary
The following chart should help admins remember how each FTP mode works:

Active FTP :
command : client >1024 -> server 21
data : client >1024 <- server 20

Passive FTP :
command : client >1024 -> server 21
data : client >1024 -> server >1024

A quick summary of the pros and cons of active vs. passive FTP is also in order:

Active FTP is beneficial to the FTP server admin, but detrimental to the client side admin. The FTP server attempts to make connections to random high ports on the client, which would almost certainly be blocked by a firewall on the client side. Passive FTP is beneficial to the client, but detrimental to the FTP server admin. The client will make both connections to the server, but one of them will be to a random high port, which would almost certainly be blocked by a firewall on the server side.

Luckily, there is somewhat of a compromise. Since admins running FTP servers will need to make their servers accessible to the greatest number of clients, they will almost certainly need to support passive FTP. The exposure of high level ports on the server can be minimized by specifying a limited port range for the FTP server to use. Thus, everything except for this range of ports can be firewalled on the server side. While this doesn't eliminate all risk to the server, it decreases it tremendously.

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Advanced Shellcoding Techniques

Introduction

This paper assumes a working knowledge of basic shellcoding techniques, and x86 assembly, I will not rehash these in this paper.  I hope to teach you some of the lesser known shellcoding techniques that I have picked up, which will allow you to write smaller and better shellcodes.  I do not claim to have invented any of these techniques, except for the one that uses the div instruction.



The multiplicity of mul

This technique was originally developed by Sorbo of darkircop.net.  The mul instruction may, on the surface, seem mundane, and it's purpose obvious.  However, when faced with the difficult challenge of shrinking your shellcode, it proves to be quite useful.  First some background information on the mul instruction itself.

mul performs an unsigned multiply of two integers.  It takes only one operand, the other is implicitly specified by the %eax register.  So, a  common mul instruction might look something like this:

movl $0x0a,%eax
mul $0x0a

This would multiply the value stored in %eax by the operand of mul, which in this case would be 10*10.  The result is then implicitly stored in EDX:EAX.  The result is stored over a span of two registers because it has the potential to be considerably larger than the previous value, possibly exceeding the capacity of a single register(this is also how floating points are stored in some cases, as an interesting sidenote).

So, now comes the ever-important question.  How can we use these attributes to our advantage when writing shellcode?  Well, let's think for a second, the instruction takes only one operand, therefore, since it is a very common instruction, it will generate only two bytes in our final shellcode.  It multiplies whatever is passed to it by the value stored in %eax, and stores the value in both %edx and %eax, completely overwriting the contents of both registers, regardless of whether it is necessary to do so, in order to store the result of the multiplication.  Let's put on our mathematician hats for a second, and consider this, what is the only possible result of a multiplication by 0?  The answer, as you may have guessed, is 0.  I think it's about time for some example code, so here it is:

xorl %ecx,%ecx
mul %ecx

What is this shellcode doing?  Well, it 0's out the %ecx register using the xor instruction, so we now know that %ecx is 0.  Then it does a mul %ecx, which as we just learned, multiplies it's operand by the value in %eax, and then proceeds to store the result of this multiplication in EDX:EAX.  So, regardless of %eax's previous contents, %eax must now be 0.  However that's not all, %edx is 0'd now too, because, even though no overflow occurs, it still overwrites the %edx register with the sign bit(left-most bit) of %eax.  Using this technique we can zero out three registers in only three bytes, whereas by any other method(that I know of) it would have taken at least six.


The div instruction

Div is very similar to mul, in that it takes only one operand and implicitly divides the operand by the value in %eax.  Also like, mul it stores the result of the divide in %eax.  Again, we will require the mathematical side of our brains to figure out how we can take advantage of this instruction.  But first, let's think about what is normally stored in the %eax register.  The %eax register holds the return value of functions and/or syscalls.  Most syscalls that are used in shellcoding will return -1(on failure) or a positive value of some kind, only rarely will they return 0(though it does occur).  So, if we know that after a syscall is performed, %eax will have a non-zero value, and that  the instruction divl %eax will divide %eax by itself, and then store the result in %eax, we can say that executing the divl %eax instruction after a syscall will put the value 1 into %eax.  So...how is this applicable to shellcoding? Well, their is another important thing that %eax is used for, and that is to pass the specific syscall that you would like to call to int $0x80.  It just so happens that the syscall that corresponds to the value 1 is exit().  Now for an example:

      
xorl %ebx,%ebx
mul %ebx
push %edx
pushl   $0x3268732f
pushl   $0x6e69622f
mov %esp, %ebx
push %edx
push %ebx
mov %esp,%ecx
movb $0xb, %al  #execve() syscall, doesn't return at all unless it fails, in which case it returns -1
int $0x80

divl %eax  # -1 / -1 = 1
int $0x80

Now, we have a 3 byte exit function, where as before it was 5 bytes.  However, there is a catch, what if a syscall does return 0?  Well in the odd situation in which that could happen, you could do many different things, like inc %eax, dec %eax, not %eax anything that will make %eax non-zero.  Some people say that exit's are not important in shellcode, because your code gets executed regardless of whether or not it exits cleanly.  They are right too, if you really need to save 3 bytes to fit your shellcode in somewhere, the exit() isn't worth keeping.  However, when your code does finish, it will try to execute whatever was after your last instruction, which will most likely produce a SIG ILL(illegal instruction) which is a rather odd error, and will be logged by the system.  So, an exit() simply adds an extra layer of stealth to your exploit, so that even if it fails or you can't wipe all the logs, at least this part of your presence will be clear.



Unlocking the power of leal

The leal instruction is an often neglected instruction in shellcode, even though it is quite useful.  Consider this short piece of shellcode.

xorl %ecx,%ecx
leal 0x10(%ecx),%eax

This will load the value 17 into eax, and clear all of the extraneous bits of eax.  This occurs because the leal instruction loads a variable of the type long into it's desitination operand.  In it's normal usage, this would load the address of a variable into a register, thus creating a pointer of sorts.  However, since ecx is 0'd and 0+17=17, we load the value 17 into eax instead of any kind of actual address.  In a normal shellcode we would do something like this, to accomplish the same thing:

xorl %eax,%eax
movb $0x10,%eax

I can hear you saying, but that shellcode is a byte shorter than the leal one, and you're quite right.  However, in a real shellcode you may already have to 0 out a register like ecx(or any other register), so the xorl instruction in the leal shellcode isn't counted.  Here's an example:

xorl    %eax,%eax
xorl    %ebx,%ebx
movb    $0x17,%al
int    $0x80
      
xorl %ebx,%ebx
leal 0x17(%ebx),%al
int $0x80

Both of these shellcodes call setuid(0), but one does it in 7 bytes while the other does it in 8.  Again, I hear you saying but that's only one byte it doesn't make that much of a difference, and you're right, here it doesn't make much of a difference(except for in shellcode-size pissing contests =p), but when applied to much larger shellcodes, which have many function calls and need to do things like this frequently, it can save quite a bit of space.



Conclusion

I hope you all learned something, and will go out and apply your knowledge to create smaller and better shellcodes.  If you know who invented  the leal technique, please tell me and I will credit him/her. 

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A Web Standards Checklist, How to make a proper website

A Web Standards Checklist, How to make a proper website

A web standards checklist

The term web standards can mean different things to different people. For some, it is 'table-free sites', for others it is 'using valid code'. However, web standards are much broader than that. A site built to web standards should adhere to standards (HTML, XHTML, XML, CSS, XSLT, DOM, MathML, SVG etc) and pursue best practices (valid code, accessible code, semantically correct code, user-friendly URLs etc).

In other words, a site built to web standards should ideally be lean, clean, CSS-based, accessible, usable and search engine friendly.

About the checklist

This is not an uber-checklist. There are probably many items that could be added. More importantly, it should not be seen as a list of items that must be addressed on every site that you develop. It is simply a guide that can be used:

* to show the breadth of web standards
* as a handy tool for developers during the production phase of websites
* as an aid for developers who are interested in moving towards web standards

The checklist

1.Quality of code
1. Does the site use a correct Doctype?
2. Does the site use a Character set?
3. Does the site use Valid (X)HTML?
4. Does the site use Valid CSS?
5. Does the site use any CSS hacks?
6. Does the site use unnecessary classes or ids?
7. Is the code well structured?
8. Does the site have any broken links?
9. How does the site perform in terms of speed/page size?
10. Does the site have JavaScript errors?

2. Degree of separation between content and presentation
1. Does the site use CSS for all presentation aspects (fonts, colour, padding, borders etc)?
2. Are all decorative images in the CSS, or do they appear in the (X)HTML?

3. Accessibility for users
1. Are "alt" attributes used for all descriptive images?
2. Does the site use relative units rather than absolute units for text size?
3. Do any aspects of the layout break if font size is increased?
4. Does the site use visible skip menus?
5. Does the site use accessible forms?
6. Does the site use accessible tables?
7. Is there sufficient colour brightness/contrasts?
8. Is colour alone used for critical information?
9. Is there delayed responsiveness for dropdown menus (for users with reduced motor skills)?
10. Are all links descriptive (for blind users)?

4. Accessibility for devices
1. Does the site work acceptably across modern and older browsers?
2. Is the content accessible with CSS switched off or not supported?
3. Is the content accessible with images switched off or not supported?
4. Does the site work in text browsers such as Lynx?
5. Does the site work well when printed?
6. Does the site work well in Hand Held devices?
7. Does the site include detailed metadata?
8. Does the site work well in a range of browser window sizes?

5. Basic Usability
1. Is there a clear visual hierarchy?
2. Are heading levels easy to distinguish?
3. Does the site have easy to understand navigation?
4. Does the site use consistent navigation?
5. Are links underlined?
6. Does the site use consistent and appropriate language?
7. Do you have a sitemap page and contact page? Are they easy to find?
8. For large sites, is there a search tool?
9. Is there a link to the home page on every page in the site?
10. Are visited links clearly defined with a unique colour?

6. Site management
1. Does the site have a meaningful and helpful 404 error page that works from any depth in the site?
2. Does the site use friendly URLs?
3. Do your URLs work without "www"?
4. Does the site have a favicon?

1. Quality of code

1.1 Does the site use a correct Doctype?
A doctype (short for 'document type declaration') informs the validator which version of (X)HTML you're using, and must appear at the very top of every web page. Doctypes are a key component of compliant web pages: your markup and CSS won't validate without them.
CODE
http://www.alistapart.com/articles/doctype/


More:
CODE
http://www.w3.org/QA/2002/04/valid-dtd-list.html

CODE
http://css.maxdesign.com.au/listamatic/about-boxmodel.htm

CODE
http://gutfeldt.ch/matthias/articles/doctypeswitch.html


1.2 Does the site use a Character set?
If a user agent (eg. a browser) is unable to detect the character encoding used in a Web document, the user may be presented with unreadable text. This information is particularly important for those maintaining and extending a multilingual site, but declaring the character encoding of the document is important for anyone producing XHTML/HTML or CSS.
CODE
http://www.w3.org/International/tutorials/tutorial-char-enc/


More:
CODE
http://www.w3.org/International/O-charset.html


1.3 Does the site use Valid (X)HTML?
Valid code will render faster than code with errors. Valid code will render better than invalid code. Browsers are becoming more standards compliant, and it is becoming increasingly necessary to write valid and standards compliant HTML.
CODE
http://www.maxdesign.com.au/presentation/sit2003/06.htm


More:
CODE
http://validator.w3.org/


1.4 Does the site use Valid CSS?
You need to make sure that there aren't any errors in either your HTML or your CSS, since mistakes in either place can result in botched document appearance.
CODE
http://www.meyerweb.com/eric/articles/webrev/199904.html


More:
CODE
http://jigsaw.w3.org/css-validator/


1.5 Does the site use any CSS hacks?
Basically, hacks come down to personal choice, the amount of knowledge you have of workarounds, the specific design you are trying to achieve.
CODE
http://www.mail-archive.com/wsg@webstandardsgroup.org/msg05823.html


More:
CODE
http://css-discuss.incutio.com/?page=CssHack

CODE
http://css-discuss.incutio.com/?page=ToHackOrNotToHack

CODE
http://centricle.com/ref/css/filters/


1.6 Does the site use unnecessary classes or ids?
I've noticed that developers learning new skills often end up with good CSS but poor XHTML. Specifically, the HTML code tends to be full of unnecessary divs and ids. This results in fairly meaningless HTML and bloated style sheets.
CODE
http://www.clagnut.com/blog/228/


1.7 Is the code well structured?
Semantically correct markup uses html elements for their given purpose. Well structured HTML has semantic meaning for a wide range of user agents (browsers without style sheets, text browsers, PDAs, search engines etc.)
CODE
http://www.maxdesign.com.au/presentation/benefits/index04.htm


More:
CODE
http://www.w3.org/2003/12/semantic-extractor.html


1.8 Does the site have any broken links?
Broken links can frustrate users and potentially drive customers away. Broken links can also keep search engines from properly indexing your site.

More:
CODE
http://validator.w3.org/checklink


1.9 How does the site perform in terms of speed/page size?
Don't make me wait... That's the message users give us in survey after survey. Even broadband users can suffer the slow-loading blues.
CODE
http://www.websiteoptimization.com/speed/


1.10 Does the site have JavaScript errors?
Internet Explore for Windows allows you to turn on a debugger that will pop up a new window and let you know there are javascript errors on your site. This is available under 'Internet Options' on the Advanced tab. Uncheck 'Disable script debugging'.

2. Degree of separation between content and presentation

2.1 Does the site use CSS for all presentation aspects (fonts, colour, padding, borders etc)?
Use style sheets to control layout and presentation.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-style-sheets


2.2 Are all decorative images in the CSS, or do they appear in the (X)HTML?
The aim for web developers is to remove all presentation from the html code, leaving it clean and semantically correct.
CODE
http://www.maxdesign.com.au/presentation/benefits/index07.htm


3. Accessibility for users

3.1 Are "alt" attributes used for all descriptive images?
Provide a text equivalent for every non-text element
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-text-equivalent


3.2 Does the site use relative units rather than absolute units for text size?
Use relative rather than absolute units in markup language attribute values and style sheet property values'.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-relative-units


More:
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-relative-units

CODE
http://www.clagnut.com/blog/348/


3.3 Do any aspects of the layout break if font size is increased?
Try this simple test. Look at your website in a browser that supports easy incrementation of font size. Now increase your browser's font size. And again. And again... Look at your site. Does the page layout still hold together? It is dangerous for developers to assume that everyone browses using default font sizes.
3.4 Does the site use visible skip menus?

A method shall be provided that permits users to skip repetitive navigation links.
CODE
http://www.section508.gov/index.cfm?FuseAction=Content&ID=12


Group related links, identify the group (for user agents), and, until user agents do so, provide a way to bypass the group.
CODE
http://www.w3.org/TR/WCAG10-TECHS/#tech-group-links


...blind visitors are not the only ones inconvenienced by too many links in a navigation area. Recall that a mobility-impaired person with poor adaptive technology might be stuck tabbing through that morass.
CODE
http://joeclark.org/book/sashay/serialization/Chapter08.html#h4-2020


More:
CODE
http://www.niehs.nih.gov/websmith/508/o.htm


3.5 Does the site use accessible forms?
Forms aren't the easiest of things to use for people with disabilities. Navigating around a page with written content is one thing, hopping between form fields and inputting information is another.
CODE
http://www.htmldog.com/guides/htmladvanced/forms/


More:
CODE
http://www.webstandards.org/learn/tutorials/accessible-forms/01-accessible-forms.html

CODE
http://www.accessify.com/tools-and-wizards/accessible-form-builder.asp

CODE
http://accessify.com/tutorials/better-accessible-forms.asp


3.6 Does the site use accessible tables?
For data tables, identify row and column headers... For data tables that have two or more logical levels of row or column headers, use markup to associate data cells and header cells.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-table-headers


More:
CODE
http://www.bcc.ctc.edu/webpublishing/ada/resources/tables.asp

CODE
http://www.accessify.com/tools-and-wizards/accessible-table-builder_step1.asp

CODE
http://www.webaim.org/techniques/tables/


3.7 Is there sufficient colour brightness/contrasts?
Ensure that foreground and background colour combinations provide sufficient contrast when viewed by someone having colour deficits.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-colour-contrast


More:
CODE
http://www.juicystudio.com/services/colourcontrast.asp


3.8 Is colour alone used for critical information?
Ensure that all information conveyed with colour is also available without colour, for example from context or markup.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-colour-convey


There are basically three types of colour deficiency; Deuteranope (a form of red/green colour deficit), Protanope (another form of red/green colour deficit) and Tritanope (a blue/yellow deficit- very rare).

More:
CODE
http://colourfilter.wickline.org/

CODE
http://www.toledo-bend.com/colourblind/Ishihara.html

CODE
http://www.vischeck.com/vischeck/vischeckURL.php


3.9 Is there delayed responsiveness for dropdown menus?
Users with reduced motor skills may find dropdown menus hard to use if responsiveness is set too fast.

3.10 Are all links descriptive?
Link text should be meaningful enough to make sense when read out of context - either on its own or as part of a sequence of links. Link text should also be terse.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-meaningful-links


4. Accessibility for devices.

4.1 Does the site work acceptably across modern and older browsers?

Before starting to build a CSS-based layout, you should decide which browsers to support and to what level you intend to support them.
CODE
http://www.maxdesign.com.au/presentation/process/index_step01.cfm



4.2 Is the content accessible with CSS switched off or not supported?
Some people may visit your site with either a browser that does not support CSS or a browser with CSS switched off. In content is structured well, this will not be an issue.

4.3 Is the content accessible with images switched off or not supported?
Some people browse websites with images switched off - especially people on very slow connections. Content should still be accessible for these people.

4.4 Does the site work in text browsers such as Lynx?
This is like a combination of images and CSS switched off. A text-based browser will rely on well structured content to provide meaning.

More:
CODE
http://www.delorie.com/web/lynxview


4.5 Does the site work well when printed?
You can take any (X)HTML document and simply style it for print, without having to touch the markup.
CODE
http://www.alistapart.com/articles/goingtoprint/


More:
CODE
http://www.d.umn.edu/itss/support/Training/Online/webdesign/css.html#print


4.6 Does the site work well in Hand Held devices?
This is a hard one to deal with until hand held devices consistently support their correct media type. However, some layouts work better in current hand-held devices. The importance of supporting hand held devices will depend on target audiences.

4.7 Does the site include detailed metadata?
Metadata is machine understandable information for the web
CODE
http://www.w3.org/Metadata/


Metadata is structured information that is created specifically to describe another resource. In other words, metadata is 'data about data'.


4.8 Does the site work well in a range of browser window sizes?
It is a common assumption amongst developers that average screen sizes are increasing. Some developers assume that the average screen size is now 1024px wide. But what about users with smaller screens and users with hand held devices? Are they part of your target audience and are they being disadvantaged?

5. Basic Usability
5.1 Is there a clear visual hierarchy?
Organise and prioritise the contents of a page by using size, prominence and content relationships.
CODE
http://www.great-web-design-tips.com/web-site-design/165.html


5.2 Are heading levels easy to distinguish?
Use header elements to convey document structure and use them according to specification.
CODE
http://www.w3.org/TR/WCAG10/wai-pageauth.html#tech-logical-headings


5.3 Is the site's navigation easy to understand?
Your navigation system should give your visitor a clue as to what page of the site they are currently on and where they can go next.
CODE
http://www.1stsitefree.com/design_nav.htm


5.4 Is the site's navigation consistent?
If each page on your site has a consistent style of presentation, visitors will find it easier to navigate between pages and find information
CODE
http://www.juicystudio.com/tutorial/accessibility/navigation.asp


5.5 Does the site use consistent and appropriate language?
The use of clear and simple language promotes effective communication. Trying to come across as articulate can be as difficult to read as poorly written grammar, especially if the language used isn't the visitor's primary language.
CODE
http://www.juicystudio.com/tutorial/accessibility/clear.asp


5.6 Does the site have a sitemap page and contact page? Are they easy to find?
Most site maps fail to convey multiple levels of the site's information architecture. In usability tests, users often overlook site maps or can't find them. Complexity is also a problem: a map should be a map, not a navigational challenge of its own.
CODE
http://www.useit.com/alertbox/20020106.html


5.7 For large sites, is there a search tool?
While search tools are not needed on smaller sites, and some people will not ever use them, site-specific search tools allow users a choice of navigation options.

5.8 Is there a link to the home page on every page in the site?
Some users like to go back to a site's home page after navigating to content within a site. The home page becomes a base camp for these users, allowing them to regroup before exploring new content.

5.9 Are links underlined?
To maximise the perceived affordance of clickability, colour and underline the link text. Users shouldn't have to guess or scrub the page to find out where they can click.
CODE
http://www.useit.com/alertbox/20040510.html


5.10 Are visited links clearly defined?
Most important, knowing which pages they've already visited frees users from unintentionally revisiting the same pages over and over again.
CODE
http://www.useit.com/alertbox/20040503.html


6. Site management

6.1 Does the site have a meaningful and helpful 404 error page that works from any depth in the site?
You've requested a page - either by typing a URL directly into the address bar or clicking on an out-of-date link and you've found yourself in the middle of cyberspace nowhere. A user-friendly website will give you a helping hand while many others will simply do nothing, relying on the browser's built-in ability to explain what the problem is.
CODE
http://www.alistapart.com/articles/perfect404/


6.2 Does the site use friendly URLs?
Most search engines (with a few exceptions - namely Google) will not index any pages that have a question mark or other character (like an ampersand or equals sign) in the URL... what good is a site if no one can find it?
CODE
http://www.sitepoint.com/article/search-engine-friendly-urls


One of the worst elements of the web from a user interface standpoint is the URL. However, if they're short, logical, and self-correcting, URLs can be acceptably usable
CODE
http://www.merges.net/theory/20010305.html


More:
CODE
http://www.sitepoint.com/article/search-engine-friendly-urls

CODE
http://www.websitegoodies.com/article/32

CODE
http://www.merges.net/theory/20010305.html


6.3 Does the site's URL work without "www"?
While this is not critical, and in some cases is not even possible, it is always good to give people the choice of both options. If a user types your domain name without the www and gets no site, this could disadvantage both the user and you.
6.4 Does the site have a favicon?

A Favicon is a multi-resolution image included on nearly all professionally developed sites. The Favicon allows the webmaster to further promote their site, and to create a more customized appearance within a visitor's browser.
CODE
http://www.favicon.com/


Favicons are definitely not critical. However, if they are not present, they can cause 404 errors in your logs (site statistics). Browsers like IE will request them from the server when a site is bookmarked. If a favicon isn't available, a 404 error may be generated. Therefore, having a favicon could cut down on favicon specific 404 errors. The same is true of a 'robots.txt' file.

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23 Ways To Speed WinXP, Not only Defrag

Since defragging the disk won't do much to improve Windows XP performance, here are 23 suggestions that will. Each can enhance the performance and reliability of your customers' PCs. Best of all, most of them will cost you nothing.

1.) To decrease a system's boot time and increase system performance, use the money you save by not buying defragmentation software -- the built-in Windows defragmenter works just fine -- and instead equip the computer with an Ultra-133 or Serial ATA hard drive with 8-MB cache buffer.

2.) If a PC has less than 512 MB of RAM, add more memory. This is a relatively inexpensive and easy upgrade that can dramatically improve system performance.

3.) Ensure that Windows XP is utilizing the NTFS file system. If you're not sure, here's how to check: First, double-click the My Computer icon, right-click on the C: Drive, then select Properties. Next, examine the File System type; if it says FAT32, then back-up any important data. Next, click Start, click Run, type CMD, and then click OK. At the prompt, type CONVERT C: /FS:NTFS and press the Enter key. This process may take a while; it's important that the computer be uninterrupted and virus-free. The file system used by the bootable drive will be either FAT32 or NTFS. I highly recommend NTFS for its superior security, reliability, and efficiency with larger disk drives.

4.) Disable file indexing. The indexing service extracts information from documents and other files on the hard drive and creates a "searchable keyword index." As you can imagine, this process can be quite taxing on any system.

The idea is that the user can search for a word, phrase, or property inside a document, should they have hundreds or thousands of documents and not know the file name of the document they want. Windows XP's built-in search functionality can still perform these kinds of searches without the Indexing service. It just takes longer. The OS has to open each file at the time of the request to help find what the user is looking for.

Most people never need this feature of search. Those who do are typically in a large corporate environment where thousands of documents are located on at least one server. But if you're a typical system builder, most of your clients are small and medium businesses. And if your clients have no need for this search feature, I recommend disabling it.

Here's how: First, double-click the My Computer icon. Next, right-click on the C: Drive, then select Properties. Uncheck "Allow Indexing Service to index this disk for fast file searching." Next, apply changes to "C: subfolders and files," and click OK. If a warning or error message appears (such as "Access is denied"), click the Ignore All button.

5.) Update the PC's video and motherboard chipset drivers. Also, update and configure the BIOS. For more information on how to configure your BIOS properly, see this article on my site.

6.) Empty the Windows Prefetch folder every three months or so. Windows XP can "prefetch" portions of data and applications that are used frequently. This makes processes appear to load faster when called upon by the user. That's fine. But over time, the prefetch folder may become overloaded with references to files and applications no longer in use. When that happens, Windows XP is wasting time, and slowing system performance, by pre-loading them. Nothing critical is in this folder, and the entire contents are safe to delete.

7.) Once a month, run a disk cleanup. Here's how: Double-click the My Computer icon. Then right-click on the C: drive and select Properties. Click the Disk Cleanup button -- it's just to the right of the Capacity pie graph -- and delete all temporary files.

8.) In your Device Manager, double-click on the IDE ATA/ATAPI Controllers device, and ensure that DMA is enabled for each drive you have connected to the Primary and Secondary controller. Do this by double-clicking on Primary IDE Channel. Then click the Advanced Settings tab. Ensure the Transfer Mode is set to "DMA if available" for both Device 0 and Device 1. Then repeat this process with the Secondary IDE Channel.

9.) Upgrade the cabling. As hard-drive technology improves, the cabling requirements to achieve these performance boosts have become more stringent. Be sure to use 80-wire Ultra-133 cables on all of your IDE devices with the connectors properly assigned to the matching Master/Slave/Motherboard sockets. A single device must be at the end of the cable; connecting a single drive to the middle connector on a ribbon cable will cause signaling problems. With Ultra DMA hard drives, these signaling problems will prevent the drive from performing at its maximum potential. Also, because these cables inherently support "cable select," the location of each drive on the cable is important. For these reasons, the cable is designed so drive positioning is explicitly clear.

10.) Remove all spyware from the computer. Use free programs such as AdAware by Lavasoft or SpyBot Search & Destroy. Once these programs are installed, be sure to check for and download any updates before starting your search. Anything either program finds can be safely removed. Any free software that requires spyware to run will no longer function once the spyware portion has been removed; if your customer really wants the program even though it contains spyware, simply reinstall it. For more information on removing Spyware visit this Web Pro News page.

11.) Remove any unnecessary programs and/or items from Windows Startup routine using the MSCONFIG utility. Here's how: First, click Start, click Run, type MSCONFIG, and click OK. Click the StartUp tab, then uncheck any items you don't want to start when Windows starts. Unsure what some items are? Visit the WinTasks Process Library. It contains known system processes, applications, as well as spyware references and explanations. Or quickly identify them by searching for the filenames using Google or another Web search engine.

12.) Remove any unnecessary or unused programs from the Add/Remove Programs section of the Control Panel.

13.) Turn off any and all unnecessary animations, and disable active desktop. In fact, for optimal performance, turn off all animations. Windows XP offers many different settings in this area. Here's how to do it: First click on the System icon in the Control Panel. Next, click on the Advanced tab. Select the Settings button located under Performance. Feel free to play around with the options offered here, as nothing you can change will alter the reliability of the computer -- only its responsiveness.

14.) If your customer is an advanced user who is comfortable editing their registry, try some of the performance registry tweaks offered at Tweak XP.

15.) Visit Microsoft's Windows update site regularly, and download all updates labeled Critical. Download any optional updates at your discretion.

16.) Update the customer's anti-virus software on a weekly, even daily, basis. Make sure they have only one anti-virus software package installed. Mixing anti-virus software is a sure way to spell disaster for performance and reliability.

17.) Make sure the customer has fewer than 500 type fonts installed on their computer. The more fonts they have, the slower the system will become. While Windows XP handles fonts much more efficiently than did the previous versions of Windows, too many fonts -- that is, anything over 500 -- will noticeably tax the system.

18.) Do not partition the hard drive. Windows XP's NTFS file system runs more efficiently on one large partition. The data is no safer on a separate partition, and a reformat is never necessary to reinstall an operating system. The same excuses people offer for using partitions apply to using a folder instead. For example, instead of putting all your data on the D: drive, put it in a folder called "D drive." You'll achieve the same organizational benefits that a separate partition offers, but without the degradation in system performance. Also, your free space won't be limited by the size of the partition; instead, it will be limited by the size of the entire hard drive. This means you won't need to resize any partitions, ever. That task can be time-consuming and also can result in lost data.

19.) Check the system's RAM to ensure it is operating properly. I recommend using a free program called MemTest86. The download will make a bootable CD or diskette (your choice), which will run 10 extensive tests on the PC's memory automatically after you boot to the disk you created. Allow all tests to run until at least three passes of the 10 tests are completed. If the program encounters any errors, turn off and unplug the computer, remove a stick of memory (assuming you have more than one), and run the test again. Remember, bad memory cannot be repaired, but only replaced.

20.) If the PC has a CD or DVD recorder, check the drive manufacturer's Web site for updated firmware. In some cases you'll be able to upgrade the recorder to a faster speed. Best of all, it's free.

21.) Disable unnecessary services. Windows XP loads a lot of services that your customer most likely does not need. To determine which services you can disable for your client, visit the Black Viper site for Windows XP configurations.

22.) If you're sick of a single Windows Explorer window crashing and then taking the rest of your OS down with it, then follow this tip: open My Computer, click on Tools, then Folder Options. Now click on the View tab. Scroll down to "Launch folder windows in a separate process," and enable this option. You'll have to reboot your machine for this option to take effect.

23.) At least once a year, open the computer's cases and blow out all the dust and debris. While you're in there, check that all the fans are turning properly. Also inspect the motherboard capacitors for bulging or leaks. For more information on this leaking-capacitor phenomena, you can read numerous articles on my site.


Following any of these suggestions should result in noticeable improvements to the performance and reliability of your customers' computers. If you still want to defrag a disk, remember that the main benefit will be to make your data more retrievable in the event of a crashed drive.

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10 Fast and Free Security Enhancements

10 Fast and Free Security Enhancements


Before you spend a dime on security, there are many precautions you can take that will protect you against the most common threats.

1. Check Windows Update and Office Update regularly (_http://office.microsoft.com/productupdates); have your Office CD ready. Windows Me, 2000, and XP users can configure automatic updates. Click on the Automatic Updates tab in the System control panel and choose the appropriate options.

2. Install a personal firewall. Both SyGate (_www.sygate.com) and ZoneAlarm (_www.zonelabs.com) offer free versions.


3. Install a free spyware blocker. Our Editors' Choice ("Spyware," April 22) was SpyBot Search & Destroy (_http://security.kolla.de). SpyBot is also paranoid and ruthless in hunting out tracking cookies.

4. Block pop-up spam messages in Windows NT, 2000, or XP by disabling the Windows Messenger service (this is unrelated to the instant messaging program). Open Control Panel | Administrative Tools | Services and you'll see Messenger. Right-click and go to Properties. Set Start-up Type to Disabled and press the Stop button. Bye-bye, spam pop-ups! Any good firewall will also stop them.

5. Use strong passwords and change them periodically. Passwords should have at least seven characters; use letters and numbers and have at least one symbol. A decent example would be f8izKro@l. This will make it much harder for anyone to gain access to your accounts.

6. If you're using Outlook or Outlook Express, use the current version or one with the Outlook Security Update installed. The update and current versions patch numerous vulnerabilities.

7. Buy antivirus software and keep it up to date. If you're not willing to pay, try Grisoft AVG Free Edition (Grisoft Inc., w*w.grisoft.com). And doublecheck your AV with the free, online-only scanners available at w*w.pandasoftware.com/activescan and _http://housecall.trendmicro.com.

8. If you have a wireless network, turn on the security features: Use MAC filtering, turn off SSID broadcast, and even use WEP with the biggest key you can get. For more, check out our wireless section or see the expanded coverage in Your Unwired World in our next issue.

9. Join a respectable e-mail security list, such as the one found at our own Security Supersite at _http://security.ziffdavis.com, so that you learn about emerging threats quickly and can take proper precautions.

10. Be skeptical of things on the Internet. Don't assume that e-mail "From:" a particular person is actually from that person until you have further reason to believe it's that person. Don't assume that an attachment is what it says it is. Don't give out your password to anyone, even if that person claims to be from "support."

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Belajar dan Tutorial IP address

Ip adress

Ip adalah singkatan dari Internet Protocol., yang merupakan sebuah alamat NIC (network interface card of controller)
atau dalam jaringan di sebuah host, dan dapat dibedakan unik berbasis TCP/IP
Tiap Komputer yang terhubung ke internet atau jaringan memiliki nomor, seperti nomor telepon, nomor ini berfungsi agar dapat menemukan satu sama lain
dan dapat mengidentifikasi dengan nomor sendiri.
Nomor tersebut disebut dengan IP address
ip address bisa berhubungan dengan dengan perusahaan internet( ISP ) kita dapat mengetahui ISP  yang dipake dari ip address kita
ip address kita mesti unik dalam arti tidak bisa sama dengan komputer lain

Adress space
ip address yang terdiri dari 32 bit disebut dengan sistem Internet protocol Versi 4 (IPv4), dalam prakteknya sistem ini terlalu rumit untuk memberikan alamat
sehingga dikembangkan dengan sistem internet protocol versi 6 (IPv6) dengan alama yang terdiri dari 128 bit

IPv4

adalah sebuah alamat IP dengan panjang total 32 bit, dapat mengalamati hingga 4 miliar host komputer atau lebih tepatnya 4.294.967.296 host di seluruh dunia
dengan perhitungan 2³² = 4.294.967.296 host
biasanya alamat IP dari IPv4 untuk membagi di bedakan 4 kelompok 8 bit dan menampilkannya dalam bentuk desimal dipisahkan dengan titik misalnya 130.94.122.197
hal ini lebih pendek dari 32 bit dan mudah untuk dibaca
tapi untuk manusia mengingat angka itu mungkin agak sulit, sehingga di pergunakan  DNS ip untuk lebih mudah membaca dan mengingat

pada prinsipnya alamat IP IPv4 dalam jaringan, di ikuti oleh bagian host, dan menunjukkan jaringan yang di rancang jaringan dan bagian host yang  merupakan host seperti contoh PC atau router
untuk kelas jaringan A (8 bit pertama adalah bit jaringan dan sisanya 24 bit host)
dalam sebuah jaringan B (alamat IP jaringan 16 bit di ikuti dengan 16 bit host)
dalam Kelas C terdiri dari 24 bit jaringan di ikuti dengan host 8 bit

tabel di bawah ini menunjukkan nilai byte pertama dan diikuti kelas jaringan  yang sesuai

--------------------------------------------------------------------------------------------
|     Nilai Byte pertama        |        Kelas Jaringan     |       Byte alamat jaringan         |
-------------------------------------------------------------------------------------------
|            0 - 126                     |                   A                 |                       1                          |
-------------------------------------------------------------------------------------------
|         128  - 191                   |                   B                  |                        2                        |
-------------------------------------------------------------------------------------------
|         192  - 233                   |                   C                  |                        3                        |
--------------------------------------------------------------------------------------------
Dalam CIDR disebut notasi garis miring digunakan untuk alamat IP,Dalam sebuah alamat untuk desimal ditandai dengan GHKL / M, di mana GM bilangan bulat, hal itu menunjukkan berapa banyak M bit dari alamat untuk bagian jaringan ke seluruh 32 bit untuk bagian host. Jaringan penomoran M bit menunjukkan menggunakan bersama subnet mask tertentu.


130.94.122.197/32 misalnya, semua bit untuk bagian jaringan dan ada sebuah host.
Jika alokasi 130.94.122.0/24 subnet sebagai telah menjadi 24 bit pertama dari alamat, sehingga tiga pertama angka desimal dipisahkan oleh periode, untuk bagian jaringan dan 8 bit terakhir untuk penghuni di dalam subnet, Akibatnya, dalam contoh ini 2 8 = 256 alamat untuk pengalamatan host individu
(Catatan: alamat pertama, 130.94.122.0, dan, terakhir 130.94.122.255, biasanya mati karena maka (sub-) masing-masing alamat jaringan adalah Alamat broadcast..)
untuk menanggapi  kekurangan ruang alamat IPv4 adalah NAT (Network Address Translation), juga dikenal sebagai IP

Hal ini memungkinkan host dari intranet dengan alamat IP dari ruang alamat pribadi dari RFC 1918 yang ditujukan, sedangkan NAT - Router ke dunia sebagai satu alamat IP dari ruang alamat routable, jadi hanya satu alamat IP tidak benar-benar diarahkan dan ditugaskan untuk, sementara ratusan host di sini dapat digunakan.

IPv6 

Sebuah solusi struktural bagi kelangkaan ruang alamat IPv4 dapat ditemukan di penerusnya: IPv6.Dalam IPv6 adalah 128 bit yang tersedia untuk alamat IP, dan sebagainya adalah batas atas teoritis 2 ^ (128) = 340.282.366.920.938.463.463.374.607.431.768.211.456 = 3,4 \ cdot 10 ^ (38) IP-adress. Seperti halnya IPv4 adalah bahwa dalam praktek lagi alamat digunakan sebagai alamat jaringan, alamat broadcast, tetapi juga jumlah besar untuk mengalokasikanalamat IP

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