Happy New Year 2013 – Best Wishes from Prohack

Happy New Year 2013 – Best Wishes from Prohack

2012 was a formidable year : ] I was busy, in fact I have never been busier in my life and I find myself guilty of going into hibernation multiple times even when I didn’t wanted to. I promise 2013 will be the year of change , and I would dedicate myself over some newer interests and projects, this time, open source ones. I had enough of closed source pentest and scouting, nevertheless, It was an year where I -

  • Completed multiple <unmentionable> targets at corp level. [4]
  • Ran IOU on my laptop and simulated complete corporate cloud over it.
  • Learnt and explored more about networks.
  • Brokeup with my girlfriend : P
  • and at last , resigned from Tulip Telecom to join Orange Business Services, a subsidiary of France Telecom. In fact I will be joining in early Jan 2013.

I hope Orange will be my home away from home and will open symbiotic and never before possible opportunities for me, and I am quite excited about it. I hope I will be able to take more time for my projects and share with you some exciting findings. When i look back at 2012, it was an year that taught me a lot of things, it was full of surprises and I hope 2013 will be an awesome year for all of us.

See you next mission and Stay Awesome .

 

Happy New Year 2013

 

Rishabh Dangwal

EIGRP Cheatsheet – EIGRP in 15 min

EIGRP Cheatsheet – EIGRP in 15 min

Long time folks, was busy with a lot of projects. Hope coming year gets less busier and I get to get my hands more dirty on networks and network security. In the meantime, here is an EIGRP cheat sheet which I thought will be helpful to folks who just want a quick theory review of Cisco’s EIGRP. Though I wanted to cover a lot more in cheat sheet like EIGRP technologies, planning but it would have defeated the purpose of cheatsheet. Never mind, I am preparing a more comprehensive EIGRP guide which I might publish soon depending on the feedback received. In the meantime, You can find the cheatsheet at Slideshare and Scribd.

 

Hacking Dominos Coupon Generator – Free Dominos Pizza Coupons & Discounts

After multiple failed attempts to place an order of pizza and getting tired of taking follow-ups from folks at Axis Bank and Bill Desk (the gateway that  takes care of Dominos's online pizza orders) , I was frustrated a lot. Then , I came across Domino's Slot machine coupon generator. An innocent looking random coupon generator that is purely JS based and is easily hackable. NOW I AM NOT SAYING I HACKED IT AND ORDERED FREE PIZZA's , the payment gateway sucks soo much that I didn't ordered anything. But yes, I do have something to share with you.

Fire up your Google Chrome (that's enough) and open

http://pizzaonline.dominos.co.in/slot-machine/process-slot.php

You will see the Coupon Generator, fill in the captcha and play it, in normal circumstances , chances are -

  • You will win a coupon , if you are feeling lucky, you can try once more and then if you win again, you will have to deal with the final discount coupon you get.
  • You will get a "Try Again", you can try till the case 1 is fulfilled.

Go to Dominos Coupon Generator

Lets turn the tables ,fire up developer console by pressing F12 .

Fireup Developer Console - the prohack.com

navigate to scripts – > slot.jsGo to Slots.js - theprohack.com

Open slots and navigate to this code

change values - theprohack.com

and change the attempts value to anything you wish

change values - theprohack.com

 

Now navigate to this code

change values - theprohack.com

and change the value to 1

change values - theprohack.com

Now time to change duration values

$('#slot'+(slots+1)).animate( { backgroundPosition:"(0px "+bgPos+"px)"}, { duration: (10000+(slots*500)), complete: function(){
limit++; //console.log(limit);
if(limit == 4){

 

Change the subjected function to

$('#slot'+(slots+1)).animate( { backgroundPosition:"(0px "+bgPos+"px)"}, { duration: (1+(slots*1)), complete: function(){
limit++; //console.log(limit);
if(limit == 4){

once done , slot timers and duration will be ultra quick.

Press Ctrl + S and click on Start / Try Again and see the results : ) Cool huh ? 

Now tinker with some innocent looking functions for your experiment : ] and enjoy.

Check this For loop and especially check for #slot values and value of i , also, some crazy things can be done by changing the pixel values

if(buttonState == 'Try Again' || buttonState == 'Please wait...'){
               var i=1;
               for(i=1;i<=4;i++)
               $('#slot'+i).css('background-position','0px 0px');
           }

Or Look for this function

$.post('process-slot.php',{ session_id : session_id},function(json){               
                var slot_result = slot_result_desc = ''; var limit = slots = 1;

 

Now again, I wont be divulging much here : P , you can modify completely the way the slot generator works and generate according to your whims : ] Work your way out.

Jackpot - theprohack.com - hacking Dominos Coupon Generator

 

PS : I did went into the site looking for coupons by being a Dominicon but the coupons there are just pathetic and almost same for all the traits like lazycon/freebicon etc.

Back to Cybernating.

Understanding DDOS Mitigation

Understanding DDOS Mitigation
Hi all,
Its been a long time since I have posted anything, sorry for the same. I hope you will be following my twitter feed/ facebook for updates of what I have been doing nowadays, if not, no problemo , I know we will still get along well. This time I will be covering DDOS mitigation methodologies which might come handy to you in long term. I actually though of hosting a free for all DDOS server for testing , but then, it didnt materialized well and I am sharing a concised view of my part which I covered . Please be noted I am only sharing what can be made public ;) 

How to Play Devil May Cry 3 SE (dmc3 se) on PC with normal controller with xpadder

Well..its been a long time I am writing a gaming article, I actually got bored of playing with routers and thought to give myself a break and return to hack and slash genre. I picked up Devil May Cry 3 Special Edition (dmc3se) for my laptop, and the game is a poor port by Sourcenext which are equal culprits in porting Onimusha 3, Resident Evil 4 on PC on behalf of Capcom , its a pity that Ubisoft (which marketed the game for PC) and Capcom wasted such a brilliant opportunity for catering PC gamers. The issues which are faced by game are -

  • Worst control scheme ever devised, controls by which only monkeys can play
  • Poor graphics and shadow effects
  • Bad joystick detection.
  • Even Worse analog stick detection and camera issues.
  • Choppy music.

If you are reading it, I guess you have already felt the pain and googled it a lot. Well, fear not , I will counter them one all : ] just read on.

Let me divide the problem into 2 categories – control issues and other issues. Well..I divided it into these two because the solution will address them in the following manner. First, Install the game properly, choose the correct directory (or whatever you want) insert correct serial key, make sure its a clean install.

Install dmc3se properly

Once you have done that, head on to Ubisoft  and download the latest 1.3 patch for your respective version. Its absolutely critical to download and install this patch for solving the issues.

download correct patch for dmc3se and install it

Once done, open the patch and install it. Your Music, graphical issues shall be solved as of now.

Solving Controller Issues

With 1.3 patch, you will be getting a utility GPadCfg.exe at your game directory for configuring gamepad. Open it and click on edit, click on the buttons in the picture and press respective button on gamepad.

open gpadcfg and configure your controller for dmc3se

Once done, DOUBLE CLICK on save button to save the config.  Dont click on L<->R REVERSE button.

once done, DOUBLE CLICK click on save

Now, your controller is mapped to game. Now go to game directory and open DMC3SE.ini . Make sure to make a backup of it though. GO to end of DMC3SE.ini and look for the section for your gamepad config. It will look like this.

Open DMC3SE.ini

Now, edit it, such that L3 and R3 (the analog buttons) are cleared.

Edit DMC3SE.ini L3 and R3

Now , download xpadder 5.3 from here . Once downloaded, open it . In case , you are using Windows 7 and it doesnt opens, right click on Xpadder.exe, go to compatibility and run it in Windows Vista SP2 mode.

change compatibility for xpadder

Also, go to folder where DMC3SE is installed, and give full permissions to the user.

give full permissions

Now open xpadder.exe, make sure your controller is connected to your PC/Laptop.  Click on controller icon to create a new profile.

configure xpadder

Go to stickds/button/dpad tab and enable and press the respective buttons.

configure xpadder for your gamepad

Once done, go to finish tab and click on close.

close and save

Once done, click on the buttons on the interface and map the LEFT ANALOG to W, A, S , D keys on the keyboard .

map to keyboard

Your final xpadder configuration will look like this.

final xpadder configuration

Save it. Now open the game and enjoy : ] , your controller will work fine.

play the game dmc3se

play the game dmc3se easily

I hope you will enjoy the game as much as I am enjoying it : ]

Emulation and Me–The gamer Side of me

First of all, sorry for a late post, I have been busy in researching DDOS mitigation solutions, and have been going through a lot of data sheets, specs and devices for the same. Also, Prohack celebrated its one more year of its technological legacy and I thought why not to cover about what made me tick and started it all..Well...to be frank, it was the games, old school games.Emulation and Me - The gamer Side of Me - prohack

The earliest memory of a videogame I played was at the local computer centre (Hind Computers) at my local town, it was Jordan Mechner's Prince of Persia in mid nineties, well..I remember the beautiful graphics on the monochrome monitors, elusive I must say, but I knew I was hooked to it for my life. It was also my first interaction with computers.

The 90's were a sort of a period when you can get your hands on an Atari (if you were lucky) , a PC (if your parents were either merchants and needed the machine for their financial transactions..or just hard-core geeks) or Terminator Ending Man series of NES clones that later in early 2000's flooded the market. The arcade scene boomed (provided you knew the places) and old CPS1 machines saw bouts of Street Fighter 2, Cadillac's and Dinosaurs (Fondly called as Mustafa due to the titular and strong character of the game) and if you were lucky Tekken 3 .

As time progressed home consoles, as I already said I witnessed 8 bit revolution in India when it was almost forgotten by the east and west. Well..not bad for me. I got my hands on an NES clone (Media 1000) for which I was able to get the Chinese/Taiwanese multicarts every once in a while, and witnessed the greatness of late eighties and early 90's in the form of Mario, Mario 3, Contra , Super C, Rockman , Mighty Final Fight, Metal Gear, Zen - The Intergalactic Ninja, Kage (Shadow of Ninja, Jap version) , Nekketsu series, Summer Carnival 92 - Recca , Little Ninja Bros,Disney’s Jungle Book, GIJOE, TMNT 3/ 4 Tournament Fighters and much much more..and to be frank, Capcom, Konami and Nintendo were my Gods .

Ending Man Taiwanese console - prohack / Photo Courtesy heimcomputer

I witnessed 16 bit gaming during my summer vacations at modded arcades at Dehradun (Tibet Coloney, Buddha temple, they are still there today), modded in the sense that they were home consoles of Sega Genesis/Mega Drive and SNES, which were fitted with Hori Style arcade sticks and hooked up to make shift cabinets, when for 5 Rs you can get your hands on Ultimate Mortal Kombat 3 , Comix Zone, Contra Hardcorps, Street Fighter 2 , Super Mario World for 30 minutes and lots more. Players duelled there and its there I got my first taste of fatalities in UMK3, and I am still good in pulling them off without breaking a sweat. Its there I had my first contact with 3d fighters like Tekken 3, Street Fighter Ex/EX2/plus , Mortal Kombat 4 and many more and I longed for my summer vacations so that I could go to my native place and play the games .

Growing up, I had my first RPG as Little Ninja Brothers by Culture Brain, when I bought the multicart, I was perplexed by the gameplay as I wasn't used to the concept of resource mining/hogging, spells, random encounters and a chained story. Getting dragstar, beating Devillion, getting to Yokan , the 7 bells..I now realise how generic it was , but back then , the sweet taste of going into an adventure in your own way was awesome. Nevertheless, I had a record of beating each game I got and mastering to the point of flawless execution, a thing that needed time which my parents frowned upon, a lot. The second thing they hated the most was the chiptune music which I liked a lot (still have a great collection of them today :) in my cell phone ) which later hooked me to the demoscene, I am a fan of the Farbrausch, .theprodukkt, Fairlight, mfx, kewlers and used to enjoy the intros/cracktros in my pastime.

Then there was Prateek, he had a blazing fast Pentium 3 at his home and I remember him cursing Windows and playing Dinocrisis (and swooning on Regina :P) , on a side note, we also started our experiments by getting a copy of Turbo Linux, experimenting with it , then after bouts of frustration and incoherent manuals (it was a time when IT WAS HARD finding the correct Linux drivers for your box, coding them was out of question since we were kids) but that's a different story. Doom , Dangerous Dave and Wolfenstein 3d was what we had with us at that time as shooters. Then after a lot of haggling, and by scoring good marks i was able to get a Sega Genesis for me (PAL version, used, with my first carts as Contra Hardcorps and Utlimate Mortal Kombat 3) and I spent my days tinkering with Super Hang On, Monaco GP, Rambo, Aladdin and lots more. It was during those days when I got a PC and then, my life was changed.

Comix Zone - Prohack
At that time, PC for me meant 3 things -

  • Games
  • Programming
  • Internet

Of which Games was the primary part and programming was done at late hours of night (VB/VBS if you are curious, it was in my courseware at school , I moved on to C as I got bored of dragging and dropping and wanted some real challenge).Initial games were Project IGI, handful of Virgin interactive classics (The Lion King..anyone ?) The real twist came when I picked up a dusty copy of Street Fighter Alpha 3 from a shop, and when I ran it from CD, a DOS based interface opened , and the game ran. But there was something peculiar about it, it wasn't exactly DOS based, I later figured out, the game ran in DOS mode using an emulator, which was a new term for me, but as a rule of thumb, anything that made me play games is something to be learnt and something to get good at, I started exploring them. I am lucky it was in those days emulation scene was still kicking ass, with fresh releases of Kawaks/Nebula/Final burn Alpha and all other CPS/CPS2/PGM emulation systems lots of documentation to read, a great community to mix and great games to play. It was then I found I had an inherent taste in emulation and I had a hand on almost all emulators which ever found their way to Zophar's Domain or scene sites. I found my own configurations that worked for me (and my own box) flawlessly, debugging through 68000 debugger in Kawaks , the first taste of loading games through Callous, and playing Super Mario World using SNES 9x (without paying money again, ever :D) .I used to play “borrowed” MAME roms on early builds of MAME and the understood the full glory of arcades . I remember playing Chronotrigger (the best RPG I played..ever) on ZSNES and dumping SPC files, only to be later converted into mp3 and then playing the sweet music on Sunday mornings. Nobuo Uematsu..thanks for making my childhood sweet.

It was due to emulators , I witnessed the actual history of gaming , starting from Spacewar to Atari, the console wars between Nintendo and Sega, the ditching of Sony by Nintendo, the revenge of Sony in the form of Playstation, the Sega 32 X, Saturn and the dawn of Sega, the tryst of Nintendo in the form of N64 , the console wars of millennium starting from the iconic date of 9/9/99 , the failing of Sega as a hardware developer and Dreamcast being ousted from market despite its innovations, the PS2 and Xbox and coming to the semi-present day scenario of PS3 vs XBOX 360 and the coming next generation of consoles.

Playstation - PSX - prohack

Later on when it came to PC Gaming, we formed the Project IGI club, guys who started their PC gaming careers with their first game as Codemaster’s Project IGI and finding new and innovative ways to beat it. Also, when it came to PC gaming, Prateek and my brother Vaibhav , both hated me for emulators, according to them it was lame and the latest was the best, I on the other had found anything with a configuration file worth my time and played through all the classic titles one by one. The only game we all agreed was awesome was Mario Kart 64 on Project 64, hell, who would argue it was bad :) Then there were PlayStation emulators epsxe/pcsx/adripsx/psx and the best plugin pack you could get your hands on – Aldo’s Plugin Pack, having the best drivers from one of my favourite coder Pete Bernert , his fantastic plugins were easy to tweak/compile (courtesy of his PE oPs project) and had exceptional performance.

Coming of age , I got my hands on Halo: Combat Evolved, CS 1.6 , Hitman series, Max Payne series of which I still can repeat dialogues of Max Payne line by line, I just liked the Nordic ,violent,noir setting of the game like with a great story line. It was also at that time I came across modern emulators PCSX2 , CXBX/DXBX, Potemkin, XEON, Dolphin,  Chankast and found except Chankast each one of them required to have an Alienware or Origin PC to even run the games (well, I wanted to play God of War at that time, bad..but they were on nascent stage then) , in laymen terms, they needed exceptionally high configurations just to croak  . I also found Doom 3 also needed an Alienware to run :| literally.

After a while, I found the emulation scene started getting stagnant with few updates and releases and I started focusing on genres I haven't tried. At this point of time, I vaguely remembered a trailer of Metal gear Solid 3 : Snake Eater in an early review at Ten Sports, and thought to give a shot to the series starting of MGS on EPSXE.

That proved to be the most exciting gaming experiences of my life.

Well..i found it alluring, awesome storyline, well developed characters, a gruff snake and the best voice acting I have ever heard on a videogame . Wow..just wow. It was time for Metal Gear Solid 2 : Substance on PC and got my copy cheap off from a retail shop. the experience ? Well..2 words – Fucking Awesome ! I will cover it in a later review some other day. Also, during those days. I saw a demo of RE4 on a gamecube machine and its still the best survival horror game ever. Speaking of which, my life had came a full circle, Capcom’s Shinji Mikami’s RE , Capcom Clover’s Killer 7,Hideki Kamiya’s Devil May Cry, Konami’s Hideo Kojima’s MGS and Shigeru Miyamato’s Mario series..Everything a gamer could want. Capcom, Konami and Nintendo..the game Gods revisited again.

Paper Mario 2 - Prohack

Mid and late 2000’s brought me Warcraft 3, StarCraft, Farcry, Half life 2 , Prince of Persia : Warrior Within (which I only play due to the refined combo system and kickass music by Godsmack) and CPS3. A special mention to Half Life 2 for the most immersive shooter of its time, although I wished the crap about G Man was solved :X . While Warcraft 3 and Starcraft are the best RTS experience, the reverse engineering of CPS3 encryption was what caught my eye during those days. One of the first POC emulators was written by Miguel Angel 'ElSemi' Horna better known as Elsemi of Nebula fame and one of the first games which I played was Street Fighter 3. Heck, CPS3 means Street Fighter 3, the finest and most technical fighting game ever made. Don't believe me ? well..just Google “Evolution 2004 Daigo” and you will know what I mean. Its the pinnacle of fighting genre only for the dedicated. Nowadays, add GGPO to it and you get a heady mix of online play in the most competitive manner in an already highly competitive game.

Street Fighter 3 Third Strike - Prohack

Nowadays, a lot of titles are revised, repacked and innovative games are being launched, you have got staples like Street Fighter 4, Killzone, God Of War 3 , Gears, RE, MGS, Super Mario Galaxy / Galaxy 2, Halo 3, Portal/Portal 2 (however I liked Narbular Drop just as much) and the innovation bandwagon of Bastion, Tower of Goo, Limbo, Bulletstorm,Journey, Infamous and a lot more..they are online and fun, the DLC allows for replayability , but still, I prefer the old school emulation any day over the current titles. Call me a nerd, but then, thats the way I am . As i type this , i have an opponent waiting for a rematch on Third Strike.

I had a great gaming childhood, if you had one, you might share my sentiments, else, I just might have some great geeky stories to tell you.

Mikrotik Routers rock– Cheap, awesome and beats Cisco at same price

Working at Tulip Telecom has his own charm, you get your hands on an array of devices and lots of research . Well, i got my hands on Mikrotik routers, i have been working on themMikrotik routers rock - theprohack.com for a considerable amount of time (more than 6 months) and they are awesome. Here’s what i like in them -
  • Awesome Router OS
  • Extensive IP accounting which can segregate and display bandwidth utilization by IP,vlan,interface,source,destination .. and even more..you name it it has it.
  • 3G modem/VPDN support.
  • Extensive Queue and filter support, with ability to use burst limits and can be extended on individual interfaces, vlan etc. its a full fledged firewall provided you know how to use it.
  • Wi-Fi support.
  • Can do Email, SMS/SMS gateway..Hell..you can even run a PHP server inside Router OS
  • Supports MPLS , BGP, OSPF, Multicast ,DHCP
  • Netflow server
  • Packet capture, Wi-Fi snooper, packet capture can be opened using wireshark
  • Scripting support to insane levels
  • Hardware encryption
  • Easy to deploy
  • Stable..and Cheap
  • and much much more..
I would prefer it over a DD-WRT/Tomato enabled Linksys any day on a tight budget :) If only people knew about it..then i guess,picture would have been different for Cisco

Increasing Reliance Netconnect speed, Online Transaction failure and Customer Care woes

Since my data card limit was over, so i got Reliance Netconnect from a colleague, thought it might come handy while posting “IP Subnetting - The easy way” at Prohack and some simple surfing, Reliance Datacards suck :|I was already skeptic of taking the data card actually as I previously had a very bad experience with Reliance Netconnect  and doubted if their broadband services are any good. I bet my MTS Mblaze makes it eat dirt any day ,but I had no option at that moment and thought , lets give the fucker another chance.

Ah well..you can say it was more than bad. Firstly, the data card has pretty bad speeds (~30 KBps) and then connection dropping issues. Mind you, I live in Delhi NCR and get full signal bars all the time on Reliance Netconnect Broadband + but still it barely managed to load Facebook. I thought, why not to change the DNS, on experimenting, I found Open DNS and Verizon DNS to be the most stable of all and I got a speed boost of 90-100 KBps : ]]

Here is how you can Increase speed of Reliance Netconnect Broadband + datacard -

Plugin your data card, launch application, go to settings, click on edit.

Reliance netconnect increase speed - prohack

Click on advanced and put DNS server IPs. I found Verizon 4.2.2.2 //4.2.2.1 and Open DNS  208.67.222.222 // 208.67.220.220 work best for me. You can also try Google DNS 8.8.8.8 // 8.8.4.4 . Experiment and pick your choice.

Increase speed of Reliance Netconnect -  DNS settings

Once done, click OK, save it and connect. you will get improved speeds..The whole process makes me wonder why Reliance’s default DNS is so slow . Do they even use their datacards at their home ? :|

On to my story, Since, even after changing DNS, the speeds were not good enough for me, so I thought, why not to recharge my MTS Data card online and then use it.  Instantly I opened MTS website and after entering required details, transferring money to MTS from my online account, the page hanged and session was timed out. Responding to my sense of deja vu, I checked the data card and found it was not sending/receiving any data. the fucker dropped the connection just I when i was about to get my transaction completed.

I guess it took its revenge :X

I immediately emailed to MTS customer care/RechargeItNow/Bank customer care and I have *yet* to receive a helpful followup message on email. I contacted MTS customer care on phone and entered 1,1,1,1,<datacard MDN number>,1 waited for 2 minutes 46 seconds (yeah..i timed it) , the automated IVR said “after several tries you have not entered any number, so we are transferring your call to our expert” . Well..it wasn't my fault, again, there is some fault in their system as I tried 3 different valid MDN numbers later on and I got the same result. Nevertheless, I was put on call with an *expert* to whom I explained my issue and asked for escalation matrix, the details of email ID and in simple words, “what to do in case of transaction failure, the MTS way ? ”

The result was flabbergasting, the CCE spoke in an english which by all means was incomprehensible to me, I politely disconnected the call and then fumed for 2-3 minutes while looking at the Reliance datacard.

Protip : If you  hate someone, gift him a Reliance datacard and watch him cry tears of blood :P

In the meantime i am still waiting for a positive response from my bank/MTS/rechargeitnow.

That was last night and I guess i have been outsmarted by a pathetic Reliance Netconnect.

IP Subnetting – The easy way

Is network subnetting driving you crazy ? Does binary math gives you headaches ? well..fear not, since the time i have delved into networks, i have gone through all the oohs and aaahs and the NAH’s of the logical crescendo , and I present you the easiest way to do subnetting. Generally,3 questions are being addressed when subnetting an IP- IP subnetting made easy - prohack

  1. No of subnets
  2. No of valid hosts and
  3. Host range/block size

We will tackle them one by one. First you need to know about IP addresses and their classes.

Class A includes 0-127 where 0 and 127 are reserved, the default subnet mask for this class is /8 .

Class B includes 128-191 in their first octet, and the default subnet mask for this class is /16

Class C deals with 192-224 in their first octet and the default subnet mask for this class is /24

Also, also, understand a simple concept, subnet masks lying between 8- 15 are A class masks, from 16- 23 are B class and 24-32 are C class masks. Furthermore, a subnet mask can be expressed as this where (N)etwork value and (H)ost values-

Class A : 255.0.0.0   = NNNNNNNN.HHHHHHHH.HHHHHHHH.HHHHHHHH  
Class B : 255.255.0.0 = NNNNNNNN.NNNNNNNN.HHHHHHHH.HHHHHHHH 
Class C : 255.255.0.0 = NNNNNNNN.NNNNNNNN.NNNNNNNN.HHHHHHHH
Class mask value          8        16        24        32

Now once you see it, lets tackle some real life questions. Lets find the no of subnets and valid hosts for 192.168.10.10/18

See this ? its a C class IP address having a mask of B class (as the mask lies between 16-24) now, in order to find the number of subnets, use the following formulae - 

2 ^ (What mask you have been provided – default mask of the IP address given)

putting the values here..

2^(18-16) –>  2^(2) –>  4 subnets

simple : )

Now for calculating the no.of hosts, use the below formulae -

2^(32- what mask you have been provided) –2

Putting values here..

2^(32-18)-2 -> 2^(14)-2 –> 16384-2 –> 16382 hosts

piece of cake ..

now to find the block size, see the provided mask lies between which next default mask value , which in this case is 24 (as 18 is greater than 16 and less than 24) . So ..

Subtract the provided mask with the class mask value which is greater than it.

2^(Next class mask value – provided mask)

which on putting values will be

2^(24-18) –> 2^6 –> 64

So, the block size will be of 64 . So, the IP addresses will be divided into 4 subnets (which we already calculated above) above as -

192.168.0.0 - 192.168.63.255

192.168.64.0 – 192.168.127.255

192.168.128.0 - 192.168.191.255

192.168.192.0 – 192.168.255.255

And the best part, its applicable to all classes : )

 

Happy Subnetting : ]