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Dan Albrich
Manager, Microcomputer Services
dalbrich@oregon.uoregon.edu
Although Microcomputer Services doesn't officially support home networks per se, we can give you some guidelines for making your home network setup as trouble-free as possible.
Note: Sharing your network connectivity between residences is generally prohibited. The sharing described here presumes family use within the same residence.
If you're already paying for a "broadband" high-speed DSL or cable modem Internet connection and have more than one personal computer in your family, it makes sense to have a home network. That way, everyone in your household can share the connectivity you're already paying for.
In some cases, a person may be paying for a DSL connection in one room of a house, yet routinely be dialing in via modem in another room of the same house. This is particularly inefficient because DSL also uses the phone line, and it actually reduces the speed and reliability of conventional modem connections. In addition, this type of setup also negates one of the best features of broadband connectivity, which is to allow Internet access without tying up a phone line.
If you have been limping along with the kind of inefficient setup we've just described, you'll definitely want to look into installing a home network.
Okay, so you think you're ready to try a home network. The first thing
to investigate is your Internet service provider's policy. Some ISPs
make it easy to share the connectivity they sell you, and others make it difficult.
Some may not allow you to share connectivity--even between your own computers
at home.
If you use DSL, there is also a practical issue you need to consider: make sure the provider gives you real Ethernet. For example, Comcast cable modems have one connector for the coax cable, and Comcast provides a real RJ45 Ethernet jack so you can connect your home PC or almost any other Ethernet-compatible device.
The only ISPs we've heard of that don't allow this type of connection are the very-low-cost DSL options that give you an internal DSL modem and no external Ethernet connectivity. If you go with the DSL option, be sure to ask for an external modem and real Ethernet connectivity.
There are two ways of sharing your connection on a home network, only one of which is recommended:
1. Single IP Address Sharing (Recommended). With this method, you use NAT (network address translation) with dynamically assigned private addresses. To build a home network, you'll need to purchase a standalone device that combines the functions of a switch (sharing the physical connection) and also provides network address translation for IP address sharing. This method is not only less expensive than buying multiple IP addresses, it also helps secure your home computers from attacks. It's both easy and inexpensive to add wireless connectivity at the same time through a single device that serves both wired and wireless connections.
2. Multiple IP Addresses (NOT Recommended). Using this method, you would connect an Ethernet cable between your cable modem or DSL modem to a hub or switch, connect your computers to the switch via Ethernet cables, and purchase additional IP addresses for each computer.
Think of wireless network access as having the same properties as a wired network (like a hub without wires). To set one up, you need a base station that's hard-wired and a personal computer (usually a laptop) with wireless capability.
A variety of wireless base stations are available, with the best allowing both wired and wireless connections. For the sake of convenience, getting a single network-sharing device with both wired and wireless may make the most sense. Any network that includes wireless, however, will be more difficult to secure. For information on securing a wireless home network, as well as an overview of wireless standards and our recommendations, see our Home Networking page at http://micro.uoregon.edu/homenetworking/
Practical How-to Guides for Apple, Linksys: For basic information on setting
up a typical home network with either Apple's Airport Basestation or a
Linksys device, see the following pages on our website (your product version
will
likely not match these directions exactly, but the principles are the same):
http://micro.uoregon.edu/homenetworking/apple/
http://micro.uoregon.edu/homenetworking/linksys/
Please do not connect a NAT box or other network sharing device (including one that supports wireless connections) without first asking permission from Network Services (346-4395, nethelp@ns.uoregon.edu). Network sharing devices typically come with a feature called DHCP for automatic IP address assignment turned on. DHCP is broadcast-based, and there should be only one DHCP server on a given network. Connecting one of these devices without first disabling the DHCP component can deny network service to other campus users. Introduction of private wireless access points may also interfere with official campus wireless service and is not generally permitted.
Packet: Data can be broken into distinct pieces or packets and then reassembled after delivery. Computers on the Internet communicate via packets.
IP address: Four numbers separated by periods, assigned to your computer. Having an IP address enables you to send and receive information.
Private IP address: Also called a nonroutable address, this is an IP address that's not generally reachable from external networks but is acceptable for internal communication.
Static Address: This is an IP address you purchase from your Internet provider that does not change over time. This type of address is the one you would typically want or need to run a server.
Dynamic Address: An IP address you purchase from your Internet provider that may change over time. DHCP is used to dynamically assign an address to your computer.
Globally Routable IP Address: This is a "normal" IP address in the sense that any computer in the world that's connected to the Internet can contact the computer having one of these IP addresses.
DHCP (Dynamic Host Configuration Protocol): DHCP enables a computer to automatically acquire an IP address on startup when connected to a network. DHCP uses broadcast, so it becomes important to have only one DHCP server on a network.
NAT (Network Address Translation): An IP sharing scheme in which one globally routable IP address is shared among several computers. Each of those computers is given a private, nonroutable address and the NAT device handles the translation. Most current home networking products use the term "router" to describe the ability to share a single IP address.
MAC (Media Access Control) address: Each network card has a unique hardware address. You can use this address to restrict access to only those computers with Ethernet addresses that match a list you supply.
Router: Routers select a path through the Internet so that a packet can reach its destination. "Router" is the term most often used by vendors to describe devices that share an IP address, although "network address translation device" would be more accurate in this case.
Hub: A simple device for sharing network connectivity. When a hub receives a packet on a designated port, it replicates that data to the other ports. In most cases, you'd be better served with a switching hub ("switch").
Switch: Also called a "switching hub," a switch reads the destination address of each packet and forwards it to the correct port. For this type of device, a switch is the thing to buy (as opposed to a hub).
AP or Access Point: This is a device that shares a wired connection with wireless clients. Think of an AP as a wireless hub.
Uplink: In satellite communication terminology, this term refers to the connection between the earth station and the satellite. On home network sharing devices, it's sometimes used to describe the connection between that device and the larger Internet (i.e., your DSL or cable modem). In the case of Linksys devices, the uplink port is either a standard port (for another device) or it can be used to connect another switch should you need more ports.
WAN Port (Wide Area Network Port): For Linksys devices, this describes the port to connect to your DSL or cable modem in order to connect to the larger Internet.
MDIX (Medium Dependent Interface Crossover): The label for the port you need to connect to the cable-modem or DSL modem. Think of it as the "uplink" for connection to the larger Internet.
SSID (Service Set Identifier): Also called "network name. Client computers must supply the network name to associate with a wireless access point. This can be used as a simple method to help keep unwanted users off your home wireless network.
WEP (Wired Equivalent Privacy): Encryption scheme used to protect wireless networks. Unfortunately, it is not very secure.