What is ARP? What is ARP Cache Poisoning? Basic Netwroking

What is ARP? What is ARP Cache Poisoning?
Address Resolution Protocol (ARP) is a protocol for mapping an Internet Protocol address (IP
address) to a physical machine address that is recognized in the local network. For example,
in IP Version 4, the most common level of IP in use today, an address is 32 bits long. In an
Ethernet local area network, however, addresses for attached devices are 48 bits long. (The
physical machine address is also known as a Media Access Control or MAC address.) A
table, usually called the ARP cache, is used to maintain a correlation between each MAC
address and its corresponding IP address. ARP provides the protocol rules for making this
correlation and providing address conversion in both directions.
How ARP Works
When an incoming packet destined for a host machine on a particular local area network
arrives at a gateway, the gateway asks the ARP program to find a physical host or MAC
address that matches the IP address. The ARP program looks in the ARP cache and, if it finds
the address, provides it so that the packet can be converted to the right packet length and
format and sent to the machine. If no entry is found for the IP address, ARP broadcasts a
request packet in a special format to all the machines on the LAN to see if one machine
knows that it has that IP address associated with it. A machine that recognizes the IP address
as its own returns a reply so indicating. ARP updates the ARP cache for future reference and
then sends the packet to the MAC address that replied.
Since protocol details differ for each type of local area network, there are separate ARP
Requests for Comments (RFC) for Ethernet, ATM, Fiber Distributed-Data Interface,
HIPPI, and other protocols.
There is a Reverse ARP (RARP) for host machines that don't know their IP address. RARP
enables them to request their IP address from the gateway's ARP cache.
RARP (Reverse Address Resolution Protocol) is a protocol by which a physical machine in a
local area network can request to learn its IP address from a gateway server's Address
Resolution Protocol (ARP) table or cache. A network administrator creates a table in a local
area network's gateway router that maps the physical machine (or Media Access Control -
MAC address) addresses to corresponding Internet Protocol addresses. When a new machine
is set up, its RARP client program requests from the RARP server on the router to be sent its
IP address. Assuming that an entry has been set up in the router table, the RARP server will
return the IP address to the machine which can store it for future use.

Very Important Tips for the Interview of Network Engineer or Network Technician

Tips for the Interview of Network Engineer or Network Technician

NC Universal Naming Convention
\\servername\shared name (It is used to access the shared folder)
Media Access Control
Primary Domain Controllers
Backup Domain Controllers
Symmetric Multi Processors
Asymmetric Multi Processing
Encrypted File System
File Allocation Table
Hardware Compatibility List
Internet Information Service
Local Security Authority
Microsoft Management Console
Organizational Unit
Remote Access Service
Remote Desktop Protocol (used for Terminal Services)
Routing and Remote Access Service
Security Identifier
Windows Internet Name Service
Globally Unique identifier
Internet Authentication Service
User Principle Name (Username@domainname.com)
Basic Input Output System
Network Basic Input/Output System
Address Resolution Protocol
Digital Video Disk
Group Policy Object (LGPO Local Group Policy Object)
Internet Protocol Security
Internet Service Provider
Network Address Translation
Master Boot Record
Universal Serial Bus
Power On Self Test
Small Computer System Interface
Simple Mail Transfer Protocol
Uniform Resource Locator
Redundant Array of Independent Disk
Intelligent drive Electronics or Integrated Drive Electronics
Fully Qualified Domain Name (full computer name)
Open Shortest Path First (these two are routing protocols)
Routing Information Protocol
Post Office Protocol (used to receive the mails)
Simple Mail Transfer Protocol (Used to send the mails)
Switch Mode Power Supply
Packet Internet Groper

Virtual Network Computing
End User License Agreement
Client Access License
Terminal Services Client Access License
Uninterruptible Power Supply
Berkeley Internet Name Domain
Pre boot eXecutable Environment
Uniqueness Database file
Light weight Directory Access Protocol
Integrated Services Digital Network
Variable Length Subnet Mask
Classless Inter Domain Routing
Internet Group Management Protocol
Flexible Single Master Operations
Automatic IP addressing
Net Bios Enhanced User Interface
User Datagram Protocol
File Transfer Protocol
Mega bits per second
directory services.directory information tree.
Internet Control message Protocol
Internet group Management Protocol
Network News Transfer Protocol
Remote Authentication Dial In User service
Simple Network Management protocol
Virtual Private Network
Layer2 Tunneling Protocol
Point to Point Tunneling Protocol
Active Directory Service Interfaces
Software Update Service
System Management Service
Windows Update service

List of important port numbers
15  Netstat
21  FTP
23  Telnet
25  SMTP
42  WINS
53  DNS
67  Bootp
68  DHCP
80  HTTP
88  Kerberos
110  POP3
119  NNTP
123  NTP (Network time protocol)
139  NetBIOS
161  SNMP
180  RIS
389  LDAP (Lightweight Directory Access Protocol)
443  HTTPS (HTTP over SSL/TLS)
520  RIP
37  Time
3389  Terminal services
443  SSL (https) (http protocol over TLS/SSL)
220  IMAP3
3268  AD Global Catalog
3269  AD Global Catalog over SSL
500  Internet Key Exchange, IKE (IPSec) (UDP 500)

How to Configure Mikrotik PPPOE Server Setup Video Training

Click and Watch Video

Step 1. Configure IP Address of Interfaces
Step2. Setting Up Mikrotik as a DNS Server
Step3. Setting up Mikrotik as a DHCP Server
Step4. Creating IP-Pools for PPOE and also for Other Network
Step5. Setting up PPOE Server
Step6. Creat PPOE SErver Profiles
Step7. Setting Firewall Rules Nat Rule is Must
Step8. Creat Default Route For Internet

Some Features of NTFS Files Sytems

Some of the features you can use when you choose NTFS are:

* Active Directory, which you can use to view and control network resources easily.
* Domains, which are part of Active Directory, and which you can use to fine-tune
security options while keeping administration simple. Domain controllers require NTFS.
* File encryption, which greatly enhances security.
* Permissions that can be set on individual files rather than just folders.
* Sparse files. These are very large files created by applications in such a way that only
limited disk space is needed. That is, NTFS allocates disk space only to the portions of a
file that are written to.
* Remote Storage, which provides an extension to your disk space by making
removable media such as tapes more accessible.
* Recovery logging of disk activities, which helps you restore information quickly in
the event of power failure or other system problems.
* Disk quotas, which you can use to monitor and control the amount of disk space used
by individual users.
* Better scalability to large drives. The maximum drive size for NTFS is much greater
than that for FAT, and as drive size increases, performance with NTFS doesn't degrade as
it does with FAT.

It is recommended that you format the partition with NTFS rather than converting from
FAT or FAT32. Formatting a partition erases all data on the partition, but a partition that is
formatted with NTFS rather than converted from FAT or FAT32 will have less
fragmentation and better performance.

How to install DHCP In Windows 2003 Server

How to install DHCP?
We can install DHCP by two ways
1) While installing Operating System
While installing Operating System, It asks at Network Settings whether u
want Typical settings or Custom Settings
Select Custom SettingsSelect Network Servicesclick on Details
Select DHCPclick on OK
2) Independently
Programs Settings Control Panel Add/Remove Programs 
Add/Remove Windows Components Select the Network ServicesClick
on properties Select DHCP OK
(During the installation it asks for CD)
Note: When you have installed DHCP a icon will appear in Administrative Tools

How to Signin Yahoo in MSN Messenger?

Msn Messenger & Yahoo, Msn Messenger & Yahoo

For All Thost Yahoo Account Holders That Whish To Use A Yahoo Account With Msn Messenger & .Net Passport Service

An Introduction

In this tutorial you will learn how to step up your Yahoo Accout with. net passport to allow u to login to msn messenger ang any .net passport supported website

What you will need

* A Yahoo Account - as thease are only obtainable via invitation i will assume you alredy have one .

* Msn Messenger / Windows Messenger - used to verify your Yahoo account.

Once you have downloaded / obtained all of thease you are ready to continue.

1. log in to your Yahoo account via -


once you are loged in minimize this internet browser window ( convenient or later on )

2. load up msn messenger and cansel any automatic signe in atempt so that you have it redy to signed in with your Yahoo account later on .

2. you will need to visit the Microsoft .Net Passport website -


3. now you will need to click on the register for your free .net passport today button that is in the top right hand corner of thepage ya cant mis it its huge

4. that will take you to a registration page fill in the from as you would if you where filling a hotmail account accept when asked for your email account you would enter myaccount@Yahoo.com

5. once the registration of you .net registerd Yahoo account has been made , signe in to Msn messenger using this newly registerd account , you will notice that when you signe in to messenger your messenger name will be youraccount@Yahoo.com (un verified ) and you wont be able to change it , this is solved below.

6. as soon as you have signed in , a message will appere in an information box ( the same as when a contact signes in ) , click on this and you will be taken thugh the process of Verifying your account the reason you have to go thogh this is because at current Yahoo is not affiliated with .net passport e.g .netpassport dosent regonise the @Yahoo.com as a valid email provider there for they cannot automatically verify your account ( hotmail and msn auto verify as there .net passport affiliated websites) ,

7.once u have been taken though the verification process you will be asked to log in to your email account and visit the url given in an email form the .net passport verifcation service , maximize the internet browser window that you signed in to Yahoo on erlier , you will have 2 emails form .net passport the first will be welcomeing you to .netpassport , the second will be the one we are after , the verification email , open this up find the url to finish verifying your email adress ( usually its either the first to thirs url in the email)

8. once you have compleeted thease actions and you have been told that your Yahoo account is verifed , signe out of msn messenger , then re signe back in ( you dont need to wait for any period of time just signe out then straight back in agane) , you will now notice the (not verifed) had been removed form your msn name , and now you are able to change ther name to , if this is so m, then congratulations you now have a fully functioning .net passport Yahoo account ( you cannot access your Yahoo email account via msn messenger you will still have to visit the Yahoo login page for this )


9. if for any reasons this didnot work , and you agane reciece the message asking you to verify , or you havent recieved your verification email from .netpassport , then re-try steps 2 - 7 , un till you get it working correctly .

i hope this helps some of you Yahoo account users out there that have been wracking your brains over how to get Yahoo in to msn messenger

Tired Of Reinstalling Windows, Solution for you

Tired Of Reinstalling Windows
My Suggestions For A Better And Easier Computing:
-> First partition ur HDD as follows. C: (primary, bootable) 10GB, D: (ur choice), E: (10 GB)
-> Next install 2 OSs, it can be XP,XP or XP,9X. One OS in C: and other E:Let OS in C:\ be called "TRASH" and that in E:\ be called "GOOD"
-> Boot into GOOD OS. Install all the important software (image viewer, winamp, winrar, acrobat, ms-office etc) in E:\program files\. Tweak all you settings, Install all the latest drivers, AV, service packs, patches etc and do the same for TRASH if you want! ALSO INSTALL THE IMAGING SOFTWARE.
-> Now boot to TRASH OS and move the "E:\Documents and Settings" to D:\ and change the default Desktop folder and My Documents folder to d:\doc & settings of TRASH OS. (right click on My Doc, Properties. There just change E: to D:\ or manually "MOVE") for changing desktop u need a tweak program (I use X-Setup, fast and free) NOW INSTALL THE IMAGING SOFTWARE.
-> Depending on ur requirements, allocate pace for D: (say 15 GB). Now OS in E: is the main OS is called GOOD (just for easy identification). and the OS in C:\ is standby and is called TRASH (again this is for easy identification)
DONT FORGET TO ON BOTH THE OS. (I use Paragon HDD Manager, it is fine. The compression is good)
-> Boot into GOOD OS. and change the default Desktop folder and My Documents folder to d:\documents and settings.
-> Boot into TRASH OS. Defragment E:. Now load the imaging program, take the image or save image to file (NOT DRIVE COPY) and store safely (if it is on secondary hdd it is good) or if dont have one, save it to different partition or save on CD.
For installing image viewer, winamp, winrar, acrobat, ms-office and other must have apps use the Program Files folder (E:\)
Now you are done!
Since documents and settings is in D:\, if u restore from image, your private files are NOT lost.The OS in C: is TRASH and the OS in E: is GOOD. These are just labels for better identification.

Use E:\ OS or GOOD as your primary OS. After this install any software utls to D:\. Sort software in categories like video, audio, dvd, cd, internet, graphics, protection etc. and install each app in thier sub-folder under the category.
If anything goes bad, goto standby OS, load Imaging app, restore the E-drive.

How to Remove WinXP Splash and See Operations

Are you having boot up problems and would like to know what it going on behind that Windows Loading Logo? To find out, you can disable the splash screen by making a small change to the Boot.ini file.

Follow these steps (carefully!):
1. Open the "System Properties" dialog box ( Settings - Control Panel - System)
2. On the Advanced tab, click the Settings button in the "Startup And Recovery" section.
3. In the "Startup And Recovery" dialog box, select the Edit button in the "System Startup" section.
4. The Boot.ini file will open in Notepad; locate the line that ends with the /fastdetect switch.
5. Position your cursor to the right after the parameter, press the spacebar, and add the /SOS switch.
6. Save the Boot.ini file, and close Notepad.
7. Click Cancel to close both the "Startup And Recovery" dialog box and the "System Properties" dialog box.
8. Restart the computer to see the effect.

Once the computer restarts you will notice that the Windows Splash Screen is no longer present. Instead you can observe some of the boot up operations that Windows XP performs during the startup stage.

To renable the splash screen, follow the same procedure but remove the "/SOS".

hOW TO CD Data Recovery? How to recover MOST of scratched CD data discs?

How to recover MOST of scratched CD data discs
I learn an old thecnique to how to recover damaged or scratched diskswith some lost of data. In this case i have one borrowed game - MAX PAYNE 2with a chunck of 4 mb lost with a scratch in CD1 Install. Here we cover somespecial thecniques of how to create a full working CD from the scratched one.
First some tools will be needed:

1. Alcohol 120%2. UltraISO3. Windows XP/2000 (not tested on 95/98/me)3. Small piece of cotton4. Dry cleaner paper5. Finally, oil for cooking.
First step - preparing the CD

Get the cotton and drop some water, start cleaning vertically the surface of CD.Do it 3 times and dry the water with a piece of dry cleaner paper. With a new pieceof cotton, drop some oil for cooking and start to wet the surface like you arewashing the CD with the oil. Dry carefully now. Some particles of oil will stay on themicrosurface of the scrath. It's okay. Seems the oil helps the laser of the CD/DVD driverto read the surface again. Sure this will work with small unreadable scratchs - some hardscratchs loose parts of the surface of the CD where we have data and it's lost forever.But if it is loosed try anyway. Whith this tip 80% of the small scratched CD's coud berecovered.

Second Step - testing the CD
With Alcohol 120% make an ISO - image making wizard - and lets see if the app canread the loosed surface. In my case Alcohol 120% had recovered 60% of the data.This is not enough. Have tryed other appz, they do not recover all the data. But theCD/DVD driver laser CAN recover all data in this case. the data is still there, what we do?

third step - making the new CD
With the main copy system of windows explorer you can do it. Just create one folderwith the same name of the CD label for future burn reference, and copy the CD contentto the folder. When the CD copy process find the scratch, in majority of the cases, it'sslow down the reading and will recover ALL loosed data.If not, it just tell you there'san unreadable sector. In this case your CD is lost. But it's not my case, finallywindows explorer got all the data from the scratch and made a copy in the folder.with the ultraISO, wrote the original CD label, drop the content of the folder andsave as Iso. You can Test the new CD just mounting the iso in the Alcohol 120%. In mycase i did ISO of the two discs from MAX PAYNE 2 and tested installing from the mountedISO. Works like a charm. I got the 4 mb lost again. So, I have burned the CD and now ihave a working copy from the scratched one.

Sounds too bizzarre, but works. Course you can jump the cleaning process and try to copythe content with Windows explorer. But in my case did not work without oil