Networking, or connecting computers together to share information, has long been one of the more difficult areas of basic computing to get a grasp on, mainly because it is one of those points at which the generally friendly user interface of your average Windows box starts showing cracks, or possibly gaping holes ready to swallow up the unsuspecting user.
Now granted, since windows 98 started the process, Microsoft's OSs have been getting progressively better at automating the process of connecting computers together, but there is still the external setup required, and if something goes wrong... well it's good to know where to look to fix it.
The purpose of this article is two-fold. First, to enable you to set up your own home network and share files between your computers, and second to make you comfortable with basic computer networking terminology and practice. Internet sharing deserves its own article, and so is not part of this one.
First, some important terms. Skip them if you know them.
Ethernet Network adaptor
An internal device that allows computers to communicate with each other via electrical signals passed through cable. Also known as a NIC (Network Interface Card).
Hub
An external device with multiple connections (ports). A computer attached to one port can communicate with computers attached to any of the other ports. They are available in many sizes, most commonly 5 ports.
Switch
Similar to a hub, but more efficient. While a hub will send data it receives from one port out all its other ports and let the computers attached to it figure out who the data is intended for, a switch stores information about the computers connected to it, then sends data only to the computer it is addressed to.
Firewall
A term for a software program or hardware device which can restrict specific kinds of data from passing into (or in some cases, out of) your network from the internet. Used for security purposes.
Cable/DSL router
Network devices which combine the functions of a switch and a firewall. They also provide the ability to easily share a DSL or cable Internet connection.
By default, all Windows operating systems use the TCP/IP protocol suite to communicate with each other through network devices. We'll look at this vital method of addressing computers on the next page.
By default, all Windows operating systems use the TCP/IP protocol suite to communicate with each other through network devices. Any computer network adaptor using TCP/IP requires 3 things to communicate with other computers: An IP address, a subnet mask for that IP address, and a default gateway. These terms will be defined in a moment. First, though, an idea of how a TCP/IP network works logically.
When you give a computer an IP address, you identify the network which it is a member of, and give it an identification number within that network. A computer in a given network can communicate with any other computer that is local to it (in the same network), provided there is a way for information to pass between them (network cables, wireless network, etc.).
Computers in a network cannot, however, communicate with computers in a different network (remote network) directly, even if they are physically connected to each other via cables.
This is where the default gateway comes in. A gateway is defined as a path out of the local network to other remote networks. A gateway can be a number of things physically, such as a DSL/cable router for your local network, a Windows server computer with multiple network adaptors split between different networks, etc. Gateways must all share one thing in common though. They are connected to at least 2 networks, and have the ability to pass traffic between them.
The default gateway assigned to a network adaptor is sent all traffic that does not belong in the local network. As an example of this, say you have a DSL Internet connection. When you connect to the Internet, you are provided with a default gateway assigned by your service provider. When you attempt to connect to a site on the Internet, the URL you type is converted into an IP address by your Internet provider.
Since this address is not going to be in your local network, the network adaptor in your computer forwards the request for the web page to its default gateway, your service provider.
From that point, your request will be passed from network to network through the internet until it reaches the local network and the data needed to display the web page starts its way back through the internet to your IP address.
That isn't where IP addresses stop, as you'll discover next.
Now granted, since windows 98 started the process, Microsoft's OSs have been getting progressively better at automating the process of connecting computers together, but there is still the external setup required, and if something goes wrong... well it's good to know where to look to fix it.
The purpose of this article is two-fold. First, to enable you to set up your own home network and share files between your computers, and second to make you comfortable with basic computer networking terminology and practice. Internet sharing deserves its own article, and so is not part of this one.
First, some important terms. Skip them if you know them.
Ethernet Network adaptor
An internal device that allows computers to communicate with each other via electrical signals passed through cable. Also known as a NIC (Network Interface Card).
Hub
An external device with multiple connections (ports). A computer attached to one port can communicate with computers attached to any of the other ports. They are available in many sizes, most commonly 5 ports.
Switch
Similar to a hub, but more efficient. While a hub will send data it receives from one port out all its other ports and let the computers attached to it figure out who the data is intended for, a switch stores information about the computers connected to it, then sends data only to the computer it is addressed to.
Firewall
A term for a software program or hardware device which can restrict specific kinds of data from passing into (or in some cases, out of) your network from the internet. Used for security purposes.
Cable/DSL router
Network devices which combine the functions of a switch and a firewall. They also provide the ability to easily share a DSL or cable Internet connection.
By default, all Windows operating systems use the TCP/IP protocol suite to communicate with each other through network devices. We'll look at this vital method of addressing computers on the next page.
By default, all Windows operating systems use the TCP/IP protocol suite to communicate with each other through network devices. Any computer network adaptor using TCP/IP requires 3 things to communicate with other computers: An IP address, a subnet mask for that IP address, and a default gateway. These terms will be defined in a moment. First, though, an idea of how a TCP/IP network works logically.
When you give a computer an IP address, you identify the network which it is a member of, and give it an identification number within that network. A computer in a given network can communicate with any other computer that is local to it (in the same network), provided there is a way for information to pass between them (network cables, wireless network, etc.).
Computers in a network cannot, however, communicate with computers in a different network (remote network) directly, even if they are physically connected to each other via cables.
This is where the default gateway comes in. A gateway is defined as a path out of the local network to other remote networks. A gateway can be a number of things physically, such as a DSL/cable router for your local network, a Windows server computer with multiple network adaptors split between different networks, etc. Gateways must all share one thing in common though. They are connected to at least 2 networks, and have the ability to pass traffic between them.
The default gateway assigned to a network adaptor is sent all traffic that does not belong in the local network. As an example of this, say you have a DSL Internet connection. When you connect to the Internet, you are provided with a default gateway assigned by your service provider. When you attempt to connect to a site on the Internet, the URL you type is converted into an IP address by your Internet provider.
Since this address is not going to be in your local network, the network adaptor in your computer forwards the request for the web page to its default gateway, your service provider.
From that point, your request will be passed from network to network through the internet until it reaches the local network and the data needed to display the web page starts its way back through the internet to your IP address.
That isn't where IP addresses stop, as you'll discover next.
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