How to Connect Two Computers

Here I am going to explain you how two computers can be commected for the purpose of sharing data or esourses. This will let you share files and folders, printers,etc.

1. Select  a Network Address

Ø  Any network address will do for this purpose.

Ø  IPv4 (IP version. 4) addresses are  like this: xxx.xxx.xxx.xxx (four number groups separated by three dots). Each number ranges from 0 to 255.  The address is divided into two portions: the network portion and the node portion.

Class A

The first number is 1 to 126 (127 is a loop back subnet used to refer back to your NIC card) - (ex. 10.xxx.xxx.xxx)

Class B

The first number is 128 to 191 - (ex. 172.16.xxx.xxx)

Class C

Tthe first number is 192 to 223 - nnn.nnn.nnn.xxx (ex. 192.168.1.xxx)

Multi-casting

The first number is 224 to 239 .

Experimental

Tthe first number is 240 to 255 .

Because IPv4 does not treat multicasting & experimental addresses the same way as other addresses they should not be used.

Ø  The network portion specifies a network; the node portion specifies an individual device on a network.

For any given network:

§  The range of all possible node portion numbers gives the Address Range.

§  The lowest possible address is the Network Address.
This address is used by devices to specify the network itself, and cannot be assigned to any device.

§  Network address is unique

§  The highest possible address is the Broadcast Address.
This address is used when a packet is meant for all devices on a specific network, and cannot be assigned to any device.

§  The remaining numbers in the range are the Node Range.
These are the numbers you can assign to computers, printers, and other devices.
Node Addresses are individual addresses within this range.

2. Connect the two computers .

Ø  To connect with a Crossover cable, simply plug an end of the cable into the Ethernet Port of each computer.

Ø  To connect with a Hub or Switch, use two straight through cables to connect each computer to the switch or hub.

3. Configuring the computers.

 Go to internet options , and go to the dialog box that lets you change the TCP/IP protocol. Change the radio buttons from "Obtain from DHCP server automatically" to "Use the following IP address:".

Ø  Give each computer a different address from the node range. Do not use the network address or the broadcast address.

Ø  Leave the "Default Gateway" and "DNS server" fields blank.

Ø For the subnet mask, use the following:

Class "A" Networks
When the first number is 0 to 127
The Mask is - 255.0.0.0

Class "B" Networks
When the first number is 128 to 191
The Mask is - 255.255.0.0

Class "C" Networks
When the first number is 192 to 223
The Mask is - 255.255.255.0

IPv4 originally used the first number (ex. 192) to determine which part of the address is network and which part is node based on the address class. However, the advent of subnetting and nonclassful networking made it necessary to provide a mask because other ways of dividing the address into network and node portions are now possible.

4. Verify connectivity.

In Windows open the command prompt which is located in the

Start Menu - Accessories - Command Prompt

 and type in: "ping [insert IP address of the other computer here] If you cannot reach the other computers address, try again setting up connection.

Sharing Files

• To share your files, right click on any folder and choose Sharing to make them shared.
• You can also do this with your printers to be able to print from one computer while the printer is connected to the other.

Straight Through vs Cross-Over Cable

• Straight through is a CAT-5, CAT-5e, or CAT-6 Ethernet Cable with the wires connected as follows:
  
  On both ends: Orange Stripe; Orange; Green Stripe; Blue; Blue Stripe; Green; Brown Stripe; Brown.
• Cross-over is a CAT-5, CAT-5e, or CAT-6 Ethernet Cable with the wires connected:
  
  On one end: Orange Stripe; Orange; Green Stripe; Blue; Blue Stripe; Green; Brown Stripe; Brown
  On the other end: Green Stripe; Green; Orange Stripe; Blue; Blue Stripe; Orange; Brown Stripe; Brown
  
  The above conforms to TIA/EIA-568 standard, however, all that is important for a cross-over to work is for pins 1 & 2 (transmit) to switch places with pins 3 & 6 (receive) on the opposite end. For a strait through pins should be the same on both ends. Color sets (ex. Orange Strip & Orange) mark twisted pairs. Keeping pin sets on the same twisted pair (i.e. pins 1 & 2 on one color set, and pins 3 & 6 on another) allows best signal quality.
• Note: TIA/EIA standard has not been established for CAT-7 or greater cabling.
• A cross-over cable is all you need to connect two computers directly.
• You may use a switch/hub with two Standard "Straight-Through" Ethernet Cables.
• Many computers can determine if you are using a crossover or straight through cable. If you are not so lucky to have auto-sensing on at least one of the devices connected by a cable, you must use the correct type between them. Computer-to-switch/hub will require a straight through, computer-to-computer a crossover.
• Check to see if your computer has an Ethernet Adapter in the back of the computer. Most new computers have this. You can tell by the documentation from the computer or by looking at the back of the computer. It looks like a phone jack, but larger, with 8-pins. Do not confuse this with a "modem" jack for dial-up phone service. Phone/modem jacks will have 2, 4, or 6 pins.

Posted in: Networking