Intel's Nehalem architecture: What's new ?

Intel's Nehalem architecture is utilized in their i7 Core processors for desktops and Nehalem based Xeon processors for servers and the following features tell you about what's new in them and why you should purchase one of these.

• High performance: The processors perform better than the amd's phenom and intel's core 2 extreme processors available in the market. The extra performance boost is always welcomed by gamers. When performance was tested on the game World of Conflict the phenom processor gave 136 fps, Core 2 extreme processors gave 220 fps whereas the nehalem architecture based processors gave out 250 fps.


• Enhanced Hyper Threading: Hyper threading technology (HTT) is a term used by intel which simply means simultaneous multi-threading which causes the operating system to interact with a single processor as if you had dual processors. So it doubles the number of threads that can be handled by the processor at one time. Thus if you have a Nehalem based quad core processor it can handle 8 threads going by the same logic.


• Turbo boost : Dynamic performance Control :-
  This is similar to Overclocking in the standard processors but unlike the standard processors where you had to manually overclock or under-clock the processor to suit your performance requirements, in this case it is handled automatically by the processor depending upon the system load. So if the load is higher it can automatically increase the clock rate i.e basically increasing the frequency and when the load decreases it automatically lowers it's clock rate.


• QPI(Quick path interconnect):- This technology is similar to amd's hyper transport technology but it is much faster than it. What the QPI does is it gets rid of the FSB(Front Side Bus) in the standard processors. The Xeon and i7 core processors provide 25.6 GB/s per link that is twice that of 1600MHZ FSB (which according to me is very fast :-) ) .
  
  The QPI architecture provides separate integrated memory controllers for each core so that instead of the memory and I/O requests sharing a bus and waiting for many cycles, the QPI and the memory bus are separate. QPI also provides separate channels for writing and reading, so these tasks can be performed in parallel.
  


• 3 Level Cache :- The dual core processors came with a 2 level cache whereas in the nehalem architecture it is expanded to 3 levels of cache. Each processor has it's own L1 and L2 levels of cache and all the processors share the L3 Level cache which is about 8MB in size. The L3 level cache contains copies of the contents of L1 and L2 caches which leads to better performance.


• DDR-3: Higher speed memory :-
  The Nehalem architecture also supports faster (so logically more expensive) RAM: The DDR3 RAM is 2wice as fast compared to the DDR-2 RAM and also maintains the same ratio when it comes to the prefetch buffer. The prefetch buffer is used to buffer the instructions for the processor when it is performing some operation and logically larger prefetch buffer size leads to better performance.


• Lower power consumption:- The Intelligent Power Node Manager for Xeon servers will automatically adjust the power for the optimum power to performance ratio (this was already mentioned when the turbo boost feature was explained). This leads to better power management and hence lower power consumption.
  

Hope this was informational enough and now that you know of the benefits of the nehalem architecture you would be in a better position to know whether or not you want to buy one of these.

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HLTV weapon models for Counter Strike 1.6

Many of you might have watched the hltv demos (.dem files) of many professional teams and may have liked the way the weapon switching looks in htlv videos. Well if you did enjoy that and would want to have those models while you play counter strike 1.6 then you can download those models from the following link.






After you have downloaded the models perform the following steps:-

• Backup the cstrike/models directory to some other location in case that you might want to revert to the older weapon models.
• Extract the weapon models into the cstrike/models directory.
  
• Launch the game and try out the new weapon models.
  

The following is the video made by someone else which shows how these models look like in game.

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Bing:The revamped search engine from microsoft

Microsoft is in its final stages for launching its new search engine named "Bing" previously known as Kumo. Microsoft will be launching it for the public soon.

Here's what the current site (www.bing.com) looks like which implies that this search engine will be out soon.


















The revamped search engine will contain the following added features:

• A left-hand navigation pane for showing related searches which is based on the semantic technology taken from a firm powerset which microsoft has acquired for quite some time now.
  The semantic technology provides an user the ability to ask questions in normal day to day language and it will be more effective and precise than google's technology. The current implementation of semantic technology in the search engine can be seen at this site.
  The semantic technology according to me is the key area where the search engine will really have to perform otherwise they'll get nowhere near to taking the competition to google.
  


• It will also provide Category breakdowns for search results


• Bringing some information directly into the results page.
  

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How to verify md5/sha1 hash

What is a Hash and why it is used?

A hash produces a fixed length output given any message and the output depends on individual bits of the data, so a change to any bit may result in change of the hash output. It is used for indexing a particular item and due to the aforementioned property it is also used for verifying the integrity of data because if a data has been changed it would not have the same hash.

/** purely informational **/
It can be produced in many ways like in sha-1 it consists of 4 levels in each level a different function is applied and 20 steps are performed in each level. A 160 bit buffer is used for storing the intermediate values, Initially the buffer contains the 5*32 register values called ABCDE. The operation is performed on 512 bit block of data. The output is produced by xoring the intial value of buffer with the value produced at the last step.
/** **/


How to calculate and verify the hash ?

There are many tools available that can calculate the hash. The tool that i will be using for explanation is FCIV that can calculate both SHA-1 and MD5 hash.

You can download the tool and learn how to use it from the following link:-







after downloading the tool in a directory add it's directory to the path variable so that it can be easily called from anywhere by invoking it from the command line (for help in setting the path variable refer to this post).

When you download a file from the internet through mirrors provided by the site it may happen that the mirror that you are using may provide you an invalid version of the file which could be a virus or spyware.

To verify that the file you downloaded is the correct one you would have to perform the following steps.

• Note down the md5 hash of the file given at the site .


• Download the file.
  


• Open the command prompt and navigate to the directory in which you have downloaded your file. let abcd be the name of the file for which you want to generate the hash . Now to produce a hash (md5) of the file execute the following command.
  
  FCIV -add "abcd" -md5 >hash.txt


• What the last command simply does is, it calculates the md5 hash and then redirects the output to a file hash.txt
  


• Now you can open the text file and compare the hash value with the value mentioned at the site. If the two values are same then file's integrity is maintained (i.e it is genuine) else you can be sure of one of the 2 things a) file was downloaded incompletely b) the file is probably a virus or malware.
  

Note:In the next post i will be mentioning about how to verify whether the torrents are fake or not.

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PHLAK:Professional Hacker's Linux Assault Kit

PHLAK is a modular security distribution. It is a derivative of Morphix, created by Alex de Landgraaf. It can be used as a live cd by security professionals to perform security analysis, penetration testing, forensics, and security auditing on a system to check whether it has been compromised in terms of security.

The thing i like the most about it is that it provides one with enough security documentation to be able to help him become a security expert. It has a file cabinet full of security related documentation for your reading/educational purposes.

This distribution comes with the best security tools like hping2, proxychains, lczroex, ettercap, kismet, hunt, achilies, brutus,nmap,nessus, snort, the coronor’s toolkit, ethereal and many others.

It also has standard features like apache, mysql ,iptables, programming compilers etc that come with the linux distributions.

It is user-friendly as it includes two fast, light-weight window managers, XFCE4 (the default) and Fluxbox.

One thing that this distribution lacks is that it is 3.5 years old and new version is nowhere to be seen whereas other penetration testing systems like backtrack are new and under active development.

Note:It's security documentation the one you'll definitely want to have.

It can be downloaded from the following link:-







Following are some of the snapshots of this os:-

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Wolfram|Alpha

What is Wolfram|Alpha ?

First thing's first Wolfram|Alpha is not your conventional search engine but is a computational engine that provides you with answers related to probably anything that has numbers or digits attached to it. It computes the answers by utilizing the structured database on the fly.

What can one do with Wolfram|Alpha ?

With Wolfram|Alpha you can get answers to your queries that may have numbers attached to it. It can answer questions related to mathematics, economics, weather, physics, constants, currency exchange and much more topics. It also provides a user with various visualizations(charts, bars, graphs) etc along with the results.

Following are some of the usage scenario's for Wolfram|Alpha:-

1. Mathematics :-

a) example query : integrate x2*sinx


























now as can be seen from this figure, it provides you with all the information you need along with the graphs of the integral function.

b) example query: 10^5 mod 35
would produce output's containing the result 5 , alternative representations etc.

these are just few of the examples, you can try your own at Wolfram|Alpha .

2) Economics :

example query: compound interest for 10000 at 5% for 3 years


























b) example query: GDP growth of countries





























3) Constants: The thing that i like the most about it is that it can compute the value of constants to as higher precision as one may want to. You just have to click on the more digits button and it will calculate the values to a much higher precision.

For ex: pi




























4) Weather and general information:

Wolfram alpha can calculate where you are by using your ip address and then provide you the relevant information.

For example:

let's say you type "weather" then it will provide you with the weather information for your city automatically by looking at your ip address. Just take a look at the following output.





























These are just few of the many possible things one can do with wolfram alpha.

Shortcomings:-

the only thing that Wolfram|Alpha lacks is that it provides old data for certain queries like "gdp growth india" in this case it provides the 2005 estimate.

The fresh data acquisition is the only thing that one would want Wolfram|Alpha to work upon.

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ddos attack/ping flooding: Explanation and Solution

what is a ddos attack/ping flooding attack ?

ddos attack or ping flooding attack is basically sending large and continuous ICMP (Internet control message protocol) echo packets to a target host and wait for the icmp reply message. Now what this does is, it floods the target host with large data segments and if ICMP service is not disabled by the target host then it will send the ICMP echo reply message (that's what an attacker wants to accomplish).

So if you want to try it out just use the following variation of the ping command:-

ping -t -l [buffer_size] "target_ipaddress"

The options:-

-t for repeated sending of icmp echo messages.

-l [buffer size] : the size of packet to be sent from[0 to 65500]

target_ipaddress : the host address you want to ping to

you can always stop the ping command like any other command by pressing ctrl+c (for windows) combination that kills the process.

For the attack to be more effective tell some of your friends a group of 10-20 people to join you and ping together an ip address.

For example:

ping -l 34567 -t 202.63.160.186

the output will be like the following image :-

The solution:-

If you are a server admin you would know about this issue and you would have probably solved this by now, but many counter strike or any other online game server admins don't know the cure for this.

Well the cure is very simple and for that you have to disable the icmp service for the wan interface of your modem/router. Now what this will do is, it will silently ignore the icmp echo request.

Follow these steps to disable the icmp service for the wan interface in the router/modem :-

• Open your web browser and type the address of the default gateway configuration page(by default it is http://192.168.1.1/index.html or http://192.168.1.1/main.html or 192.168.1.1) and then type in the user-name and password pair (by default are admin, admin or admin, password) .


• Now, first find the management section in the configuration page, then the access control configuration page and finally the services config page (don't worry if you cannot find the exact sequence the important thing is that you must be able to find the service configuration page)


• Uncheck the icmp service, save the changes and after saving the changes you might have to reboot the modem so reboot it. Now any ping request to your modem's wan interface will be warded off (and counter strike admins will be able to run their servers with no lag due to this attack) (Refer to the following snapshot of my modem page which is a beetel 220bx)

Note:If you have any issues do post your comments.

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Usenet Guide

This guide will be a walk through on how to use usenet.

What is Usenet ?

Usenet is basically is a worldwide distributed internet discussion system containing wealth of information. It is basically based on client server architecture. Usenet information is spread across many servers across the world or internet so there is no central entity in managing it. It was heavily dominant before the existence and being of web and still provides knowledge not easily accessible through web. It is likely that you have not heard about it because web is now dominant and usenet is an obscure entity. But usenet is still the place where you can find consummate knowledge articles.

Usenet guide

1. Installing a client:

There are many usenet clients available on the net installing a client is necessary because it lets you view the messages in newsgroup and download them from a Usenet server. As usenet is a client server based entity so installing a client is neccessary.

Following list contains a number of usenet clients you can download anyone of them:

• Bnr2 ( Binary News Reaper) : It is a freeware and is basically tailored for reading articles from alt.binaries.* group.
• Xnews: It is a freeware client.Xnews features a quick filter, a score file for more advanced filtering, support for multiple servers and identities, binaries handling, optional header and article caching, and folders for permanent archival.
  
• Newsbin: It is not a freeware.It is used for downloading files from newsgroups. Also it automatically combines complicated multi-part binary posts to create one file.
• Grabit: It is a freeware but it's search feature is paid. One can download the content without having to download entire headers. It boast of a feature to automatically repair and extract of downloaded binaries.

2. Getting a Usenet Server:

It is the place from where you can download the usenet content i.e the content from the newsgroups.

I mention here a site that contains a list of free Usenet servers you can go to this site and choose the server you want.It is to be noted that only the servers in white text are active at any instant of time. This site maintains and updates a list of public news servers everyday.

Visit www.disenter.com for server list.

3. Usenet Search Engines:

This is a place where you can search for keywords across numerous newgroups and they provide nzb support. Nzb file contains details of the item to be downloaded, to make it more clear think of nzb file as a torrent and usenet client as the client that downloads that file for you.

Here's the list of usenet search engines:

• Binsearch.info
• www.newzsearch.com
• issociate
• Newzleech
• yabsearch.nl

This guide just provides you with basic information that you would need to get started with usenet. If you encounter any problem with client setup or any other query then post your comment.

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