Andrew, all that terminology can certainly be confusing, especially when there's no reason to use most of it. For your home, you need a router, plain and simple. A switch, and a hub, are necessary on larger networks - they're essentially bridges on a network, connecting multiple parts of a network together, but don't provide the function of a network router, which is important to you.
A router functions as a "gateway" to the internet. It sends information from any of its connected computers, to the internet, and recieves information from the internet, and decides which computer it should go to. In the simplest sense, a "router" connects two networks, yours and the internet, while a "hub" or a "switch" connects two computers in a network.
Most routers in the modern day actually provide both functions, fortunately, limiting the hardware you have to buy to a single item, plus one card for each computer. They also usually have firewalls built-in to them, although you should check the specs of the routers to make sure. It's not a bad idea to have both hardware (router) firewall, and software (operating system) firewalls, running - if you decide one computer is a 'gaming' computer and needs more open ports, while one is your 'banking' computer and needs ultimate security, this allows you to do that. Windows XP fortunately comes with a built-in software firewall, so you don't need to buy anything else.
What hardware you buy depends on how you are setting up your network. A "wired" network simply requires each computer have an ethernet port (which many have built-in, but if not you can buy as an expansion card for about $10-$20). You also buy a wired router, which will run you about $30-$40, or a wireless router for $50 or so if you prefer flexibility - most wireless routers have at least 4 connecting ports for ethernet cords. Then plug the cords into the router, plug the router into the DSL modem, and set up the router using its set-up software - and you're done! Piece of cake.
A wireless network is not much more complicated, until you get into security features. You need to buy a wireless card for each computer that is connecting via wireless, and an ethernet port must be on any computer that will be wired in directly. One computer should be wired, if possible, to allow more secure options to be set (such as requiring only a wired connection be able to set router options). It helps if you buy all from the same manufacturer, but it's not required - wireless networking is very much a standardized business, and LinkSys cards will connect to a DLink router, etc. They simply have more similar set-up options that can make that a bit easier, if they're made by the same company. Then, buy a wireless router, around $50 or more depending on what type you get (802.11b, 802.11g, Pre-N, etc.) - see other articles on CNET on how to choose which type to buy. After that, it's just a few set-up options on the router and on the individual computers, and you're set!
One last thing - your DSL modem. Although most DSL modems are simply that - modems - several companies now make DSL modems that include the functionality of a wireless router. Your DSL provider can tell you if that is an option for you. More than likely, this is a more expensive option than simply buying a separate router, but you may prefer to have fewer boxes and fewer plugs.
Submitted by: Joe M. of Chicago
I understand your confusion on the subject. There are a lot of devices out there. What's even more confusing is the devices that have multiple functions (the famous "All-in-one boxes"). In the SOHO (small office/home office) market these seem to be the most prolific of the devices that are available. An explanation about how each device works can help you understand how one of the All-In-One boxes work.
To understand some of this you need to have a little back ground in something called the OSI (Open Systems Interconnect) model. The OSI model provides "an open system networking environment where any vendor's computer system, connected to any network, can freely share data with any other computer system on that network or a linked network." as defined by Newton's Telecom Dictionary, 19th edition. Sounds like what we want to do right?
The OSI model has 7 levels but what we will be concerned with are the bottom 4, because the devices in question operate in the bottom 4 levels. Here are the 7 levels:
2 Data link
"The physical layer conveys the bit stream - electrical impulse, light or radio signal -- through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier, including defining cables, cards and physical aspects." This is the layer that Hubs operate on.
"The Data link layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the Physical layer. The addressing scheme is physical which means that the addresses (MAC-Media Access Control) are hard-coded into the network cards at the time of manufacture. The addressing scheme is flat. This is the layer at which bridges and switches operate. Connectivity is provided only among locally attached network nodes."
"The Network layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer. The Network layer performs network routing, flow control, segmentation/desegmentation, and error control functions. The router operates at this layer -- sending data throughout the extended network and making the Internet possible, although there are layer 3 (or IP) switches. This is a logical addressing scheme - values are chosen by the network engineer. The addressing scheme is hierarchical."
"The purpose of the Transport layer is to provide transparent transfer of data between end users, thus relieving the upper layers from any concern with providing reliable and cost-effective data transfer. The transport layer controls the reliability of a given link. Some protocols are stateful and connection oriented. This means that the transport layer can keep track of the packets and retransmit those that fail. The best known example of a layer 4 protocol is TCP."
Now I've given you a little information and you're probably wondering, " How does this relate?" Well, let me elaborate a little.
A Hub is a Physical Layer device that repeats EVERYTHING it receives to all ports. We call it a "dumb repeater". You can send information from one computer to another in this way. The problem with this being that if another computer sends a packet at the same time as your computer i.e they transmit at the same time you get a collision. Both computers then have to back off for a random amount of time and then retry their transmission. On a hub only one computer can talk at a time and all computers must talk at the same speed. A Hub creates what is called a collision domain , basically a place where packet collisions can happen. This is a very inefficient way of networking. The flow of information is restricted, kind of like a conference call. Only one device is allowed to "speak" at any given time. This is called "half duplex" meaning that only one device can speak at a time and then listen for the response.
A word about network interface cards (NICs) and packets/frames. NICs actually have a burned-in non-changeable address called a MAC address or Layer 2 address (see data link layer definition). There is also a user-definable IP address (a.k.a. Network address or layer 3 address) that can be statically assigned or assigned by the operating system (in your case windows XP) or by a DHCP server. When an ethernet frame is formed it includes several things:
An ethernet frame header with source and destination MAC addresses
The IP header with source and destination IP addresses
The information that needs to be sent across the network
Basically the ethernet NIC stacks these up like so:
ethernet header---IP header---TCP/UDP header---Information
Now back to our explanation of devices
A switch is more intelligent and efficient. It will read out of the layer 2 header, the source and destination MAC addresses. It records the source address into a table that correlates MAC address to the port. It then sends the frame only to the appropriate port. It does NOT repeat the frame to all ports. This means that each port becomes it's own collision domain. This solves any issues with collisions and retransmissions. If another port needs to talk to a port that is busy then the information is passed to a buffer memory block for that port. This also allows the ports to have different speeds i.e. one port can be 10baseT and another port can be 100baseTX and they can still talk. Additionally the switch usually allows for full-duplex operation. Full duplex operation means the NIC in your computer can transmit and receive at the same time (with half duplex you could only transmit or receive but not both at the same time). This means you can send twice as much information. Theoretically, with 100baseTX this would mean 200Mbps. A switch will generally pass traffic from port to port at full wire speed.
A router or Layer 3 switch actually looks a little deeper. The router will strip the ethernet header off the frame and then read the source and destination IP addresses in the IP header. It then checks it's routing table for which port the IP address is located out of and forwards the packet to that interface or "next hop" router. The router (and most firewalls) can also read the TCP or UDP header for the packet (it is layer 4 aware). Routers are generally used to connect Local Area Networks (LANs) to the Wide Area Network (WAN). Since the WAN connection is usually slower you will typically get less than wirespeed from the LAN interface (ethernet or token ring) to a WAN interface (such as serial, T1, ISDN, DSL). Usually a router is also able to do other functions above and beyond just routing including access control lists, NAT (network address translation), PAT (port address translation- sometimes referred to as NAT overload) ,DHCP etc.
A firewall is also a device that can look into L2/L3/L4 headers and make decisions. There are several different types of firewall:
Packet Filtering firewall (a.k.a. Access control list firewall)
NAT firewall-firewalls that use NAT/PAT as their primary defense.
Stateful inspection firewall- inspects all inbound packets for malformed packets
Proxy firewall- Using a proxy server as a type of firewall
Transparent firewall- Is a Layer 2 type firewall designed for LAN-to-LAN firewalling where NAT and routing is not taking place
Generally you have at least 2 ports on a firewall and sometimes many more. You will usually have an untrusted (or outside) port (usually ethernet), and a trusted (or inside) port (also usually ethernet). There is also a third type of port called a DMZ port that can be used for devices and servers that need to be internet facing. e.g a web server or FTP server.
The best types of firewalls include multiple functions such as stateful inspection, NAT, and packet filtering. Unfortunately usually a firewall on SOHO type devices is a combination of NAT/packet filtering. It's not all bad though. This can still be used effectively to protect your computers from attack in many cases.
Now combining the Switch, router and firewall functions into an all-in-one type device would give you (on most SOHO devices) a firewalled WAN ethernet port to connect to your DSL or cable modem and 4-inside ports on a LAN side switch that are NATed to the outside public IP address (on the WAN port). Usually these devices include a DHCP server that automatically assign your LAN IP addresses and the WAN port acts as a DHCP client and pulls an IP address from your ISP. This will allow you to send traffic across your private internal network and share your internet connection. An example of equipment is a Linksys BEFSX41 or Netgear FR114PNA. Sometimes manufacturers also include a wireless access point in the mix e.g. Linksys WRT54G or D-link DL-524.
You can split the functionality into 2 or 3 devices. However, this will cost you more as you would need to buy a router, a firewall, and a switch and is usually a MUCH more complicated installation and configuration. OR you might buy a router/switch combination and install firewall software on each computer. (I don't consider the firewall on windows XP SP2 to be adequate for the job). I wouldn't suggest this, because it leaves your network open to hacking even if you have a good firewall software on each computer (such as Zone Labs' Zone Alarms personal firewall, or Norton Internet Security, or Mcafee Personal Firewall) and the cost of the firewall software may become prohibitive as well.
With the functionality and ease of setup on the new SOHO devices I would suggest a router/firewall/switch combination at this point for your network. At a later time you should be able to add another switch for any expansion you may have and you can get some router/firewall/switch combinations that include wireless AP functionality (remember to secure wireless if you use it or if you don't, turn it off ). I would also suggest that you still run spyware/adware-detection software and antivirus software on each computer.
Hope this helps!!!
Submitted by: Nathan H.
To set up the very simplest network at home, all you need is a 'cross-over' cable and two computers, each equipped with a network interface card (NIC). This can be a convenient way to transfer information from an older machine to a newer one. You can purchase a network cross over cable at any store that sells computer cables.
However, since you mentioned 3 machines and internet connection sharing, we must create a full network. The old way of doing this, is to use a 'hub', and 3 lengths of networking cable. A hub has no intelligence to speak of; all the lines are electrically connected to each other, and a signal that is present on any one of the lines, is replicated on all of them. Hence, if you are sending a signal from computer 1 to computer 2, that signal will travel from computer 1 to the hub, where it will be replicated on the line going to computer 2... AND on the line going to computer 3. (When the unwanted signal arrives at computer 3, the NIC card looks at it, determines that it is not intended for computer 3... and ignores it.) As you can see, a hub can create an awful lot of unnecessary network traffic.
Routers, by comparison, have some built in intelligence. When you send a signal from computer 1 to computer 2, it travels from computer 1 to the router. The router then looks at the signal, determines that it's intended for computer 2, and sends it out along ONLY the line intended for computer 2.
At one time, in the dim, distant past... like, a few years ago... hubs were cheap, and routers were very expensive. Now, you can buy a deluxe, wireless home router for $40 or less. For this reason, routers have become the common choice in creating a home network, and sharing out an internet connection amongst computers. Hubs and switches are now pretty much legacy items.
I should also mention that routers provide a cable input as well, which can be used for sharing an internet connection out to all computers connected to the router. However, some - not all - broadband Internet Service Providers restrict the number of IP addresses that can connect to the internet through the connection they rent to you. (An IP, or Internet Protocol, address is simply a string of numbers which uniquely identifies your computer on the internet. Just as your house number uniquely identifies your house, your IP address uniquely identifies your computer.) Since the router will have it's own unique IP address, you may need to contact your ISP and ask them to add the routers IP address to the list. Alternately, some modern routers have a function whereby they can 'clone' your existing computer IP address, which gets around this problem.
Regarding firewalls, many network professionals consider that a router is a pretty effective firewall, in that it contains a unique IP address that looks like your computer, but is not. On the systems I configure, I also activate the Windows XP firewall (and when I'm working with older operating systems, I use Zone Alarm.) This gives you an extra layer of protection; and in the world of computers, there is nothing remotely resembling too much security.
It is common these days for routers to include a wireless option; that is, if you have a wireless network interface card on the computer, the router can communicate with it by means of a radio broadcast, thus eliminating the cable. It is increasingly common to see manufacturers include wireless network cards built into both portable computers and even PDAs. As a result, this can be a very convenient way of connecting your new laptop or PDA to the network; you can surf the net while lounging on the patio, without ever having to string a cable.
However, it's important to remember the 'B' word: Broadcast. When you broadcast a signal with a wireless router, two bad things can happen. First, your internet communications can be intercepted and viewed by a third party. Second, a third party can access your network, thus gaining access to your computers, and to the internet if your machine is connected. This has become a common method of access for people that want to do Bad Things on the internet - say, launch a new virus, or look at child pornography. There have even been cases where Bad People have created a hidden folder and stored illegal files - typically, the most obscene child pornography imaginable - on a targetted home computer, without the owners knowledge. And when the FBI traces the illegal surfing back to find the originating computer, guess whose computer they trace it to? Yep - your computer. Try and explain THAT one to your wife, your boss, or your minister. Of course, you could always let your lawyer do the explaining; you'll need an expensive lawyer anyway, to represent you in court on the inevitable - and very serious - charges.
By the way, many people believe that they're safe using a wireless network because networks only work over a sharply limited range - say, 300 feet. That's true if you're using the default antennas that come with the wireless network cards. But if you substitute a higher gain, directional antenna - and there are many designs easily available on the net, some of which can be made with nothing more than a Pringles potato chip can and a bit of wire, tape and glue - you can dramatically increase the range. I think the unofficial hackers record is something over 20 miles, but I haven't checked lately. Suffice to say, even a modestly talented amateur can find your signal from many blocks away.
You can keep your network secure by doing two things. First, enable data encryption on the router; the exact method varies from router to router, but it's explained in the instruction manual. Basically, you supply a password, and without that password, it is (almost) impossible to connect to the network - or view the encrypted data stream. The second thing you should do is apply a filter that will restrict the network to accept connections from a listed set of MAC addresses only. A MAC address is a kind of 'serial number' built into the network interface card on your computer. By telling the router to accept connections from only those MAC addresses in the specified lookup table, you prevent outside computers from connecting, even if they do manage to guess your network password. Again, the instructions for applying these - and other - filters are in the instruction manual that came with the router.
There is no such thing as impenetrable security; but by doing these two things, you can make your home network so difficult to penetrate that a bad guy will throw up his hands, and go after an easier target. There are lots of easier targets, after all; not everyone reads CNET.
So, to summarise: the most practical way to create a small network is to use a router, not a switch or a hub. Internet connection sharing is easily achieved with a modern router. Wireless routers are common, inexpensive and very convenient, but they carry potentially disastrous security considerations with them; and you MUST apply the correct security precautions in order to use them safely. Don't depend on the limited range to keep you safe. A router can provide much of the protection that a firewall provides; but I use a software firewall as well, simply to provide an additional layer of protection. The windows XP firewall is quite adequate.
I hope you enjoy your network!
Submitted by: Charles W.
What would work best for you would be a 4 port 10/100 Router, this will provide 3 connections, 1 for each of your systems and 1 for your modem (DSL/Cable). If you think you might want to hook up other items, you might want to invest in an 8 port variety - many things nowaday's can use it, such as game consoles, home entertainment systems, etc...
The different types of network devices you question are described briefly in laymans terms below:
Hub: simple movement of data across a network, all connections share the same bandwidth. Does not in itself allow network communication as there is no 'Traffic director' (aka DHCP/DNS in technical terms). These have mostly been replaced in usage by switches, due to falling costs.
Switch: Very similar to hubs, but allow direct connection between communicating systems. No 'Traffic Director' to allow general communication between systems.
Router: Encompases the functionality of switches, with the addition of a 'Traffic director' which assigns addresses to connected systems so that they may communication. Most popular routers used at home nowadays also include a Firewall, which helps prevent unwanted communication to pass through in either direction, as desired.
Something else you might want to consider - Wireless, wireless routers are fairly inexpensive and allow the extra dimension of not requiring you to hardware your systems to the router, and the attendant drilling of holes, etc. involved (tends to make wifes happier). The current 802.11g standard is fairly fast (generally about 54MB/s) although speed will depend on distance, obstructions, etc... and again, many devices will be using this now and in the future. A side-benefit is expandibility, 802.11g allows for 254 connections, which should cover the needs of most home users. One thing to remember however is that if you do use a wireless, be sure to enable security (WEP128 is fairly easy to set up and secure - there are many other options however), otherwise anyone can potentially gain access to your home systems and/or you internet connection.
Submitted by: Jeff L.
Andrew, it is confusing, but it is actually quite simple to put your system together - but there are several levels of simplicity.
A hub is conceptually just a splitter box. You plug in one Ethernet connection and it connects that cable to all the other plugs on the hub.
(It's actually more than just wires, but that's not important to understanding it.) It knows nothing about sources or destinations; you use it when you need to run a network cable to two or more places. Hubs provide no networking functionality for your DSL problem.
A router, on the other hand, is a major part of your DSL-based network.
Depending on the router, you may have to come to terms with what IP addresses are. Assuming that you have the type of DSL service that assigns itself an IP address automatically (this is called DHCP), things are simple.
Routers are devices that connects different computers together according to source and destination address. Your router will have one Internet (IP) address that the DSL line sees. This is because the DSL service can only work with one address at a time. The other connectors on the router make the connected computers look like they have the same address, thus "fooling"
the DSL into thinking there's just the one. However, each computer will think that it's looking at a unique address, because that's what computers want to do. That's it really.
A switch technically connects different networks together. It has become common to incorrectly say "switch" when "router" is meant but there is no harm done. Back in the days when "normal" (10MBps) Ethernet was about as common as "Fast" (100MBps) Ethernet, you would use a switch to connect devices of different speed together. Almost everything supports 100MBps Ethernet nowadays. But switches may make a comeback as people start mixing Fast Ethernet and Gigabit Ethernet. You will not have that problem at this time.
Most routers have hardware firewalls. This is good. But when they work with software firewalls, the firewalling can become too restrictive and you might not be able to connect to anything. I have not had this issue occur with Windows 2000 or XP, so I just leave all the firewalls on.
You'll have to configure your router. Most of the router installation programs will do this for you. My own SBC-branded equipment collected all of the pertinent information itself, and worked with zero problems on Mac, Win, and Linux. For other devices, the rule is to read the manual; configuration is usually simple, and most manufacturers have pretty good support, if you're willing to spend half an hour on hold!
Best of luck to you. You'll have a great experience once your system is up and running.
Submitted by: Thomas B.
I'll start by going after your first question, what's the difference between a router, a switch and a hub?
A router is simply a device that forwards data packets over the network. A packet is part or all of a message sent from a computer that includes the address of the computer it needs to go to (destination). A router is connected between two networks, in your case it would be connecting your three computers on a network of their own (also called a LAN or Local Area
Network) to the Internet. Routers are located at gateways which are just entrances to another network, in your case your DSL modem is the gateway to the Internet. To put all that mumbo jumbo in perspective, the gateway is like a toll booth and the router is the road leading to and from that toll booth.
A switch is a device that filters the packets between segments of a LAN.
This means that the switch looks at the data in the header of the packet and decides where it needs to go. The header of the packet tells network devices what computer sent it, what computer it is for and how much data is in the packet. Switches usually have several segments (also called subnets) connected to them. They forward packets to the right segment and keep them off segments they don't need to go to. This keeps the network from feeling like the congested roads in Florida during Spring Break.
A hub is just a common connection point for everything on a network segment.
In your case you will have just one segment (very simple). Hubs contain multiple ports and when a packet is received by the hub, it gets copied out over all the other ports. This means that every computer on the segment will get that packet, but only the computer it is addressed to will do anything with it. That said, plain hubs make for congested networks (the Florida Spring Break Syndrome) if there are a lot of packets going back and forth.
All that said, the dumber the device the cheaper it is. So it goes from Hub to Router to Switch (dumbest to smartest). The smarter the device, the more it tends to cost. However, the good news for you is that broadband routers (the kind for DSL and Cable Modem connections) are not very expensive these days. I would suggest that you get a good broadband router that also has network ports in it. I personally have a Cisco/Linksys router that also has wireless in it. Unless you plan on having a notebook with wireless networking built in or you are using wireless networking to connect your three computers together, you won't need a wireless model.
The answer to your next question - "do I need all of them?" You will be happy to know (as I also pointed out in the last paragraph), no you do not.
Today's broadband routers have many options and as I said before, some of them come with a set of ports built-in for networking. So I would say that a broadband router is all you will need there. In answer to your next question about firewalls, yes many of these units have firewalls in them as do many DSL modems. However, the DSL modems tend to have weak firewalls at best.
Many of the Cisco/Linksys models (not sure enough to say all of them) have firewalls built into them. Mine does and it made a big difference for me.
Even though these devices have firewalls built-in, it is still a good idea with the many threats popping up these days to have a software firewall as well. I know that Windows XP Professional has a firewall option included (not sure about Home edition). But you can also go to CNet's Download.com and look at the many options there - some are even free. One that I have seen spoken highly of a lot in many places, and I use at home, is Zone Alarm (www.zonelabs.com).
One last thing I would like to add is to read the startup information carefully and understand it before you jump into configuring your network.
Many of these devices come with a basic configuration so you can just plug and play. But if you read the instructions, you will find that there are more options available that allow you to change the defaults and improve security as well. As always, if you need help, the CNet community is here to help as best we can. I wish you all the best and I hope you have fun with and many returns on your network project.
Submitted by: Chris S. of Tucker, GA
First off, the good news is you don't need one for each computer.
That should make your bank account happy. While they all serve a similar purpose (linking several computers on a network) they are very different from each other.
A hub is the least sophisticated of them all. When data is sent over a network, there is a destination address for each packet of information. A hub is simply a central location where all the data is sent regardless of it's destination address. This data is then available to all the computers (ports) on that network.
A switch on the other hand, reads the destination address and sends it to the correct port (connection for another computer) so the data can get to it's destination more easily.
A router is the most advanced. Strictly speaking a router is used to connect multiple LANs (Local Area Networks) or a LAN and a WAN (Wide Area Network, i.e. Internet), but most today have a switch built in.
That allows them to be the backbone of your network and allow your network to connect to the Internet. These are basically little computers that route traffic not only among each of your computers but also to and from the Internet. They contain all the advantages of a switch, but usually offer a firewall and many other features as well.
As an example, this is how my network is setup. First I have a router. Mine has wireless built in so my friends and I can use it with our laptops without dragging a bunch or cables around. The router has a WAN connector on the back which is connected to the Internet, the other connectors are used one for each computer. A small router usually has 4 ports, which would be enough for your three computers. However you may need to add more later. This is where our old friend the switch can come in. I have a 5 port switch connected into one of the ports on the router. This allows 4 more computers to connect through the switch. I use a switch in this case because I want something to send the data to the correct port (not a hub), but I did not need or want another router. A router in this case could be more difficult to set up and is far more advanced then I needed (not to mention more money).
Submitted by: Jarrod R.
Andrew, you are not alone experiencing the confusion surrounding this subject, as most routers today combine the features and function of a router and switch/hub into a single unit. They may also embrace a built-in modem!
The functions of a router, hub, and switch, are actually quite different from each other, even if they are, at times, integrated into a single device. Each serves as a central connection for all of your network equipment, and handles the transmission of data frames in a different way.
A switch keeps a record of the Media Access Control (MAC) addresses of the devices connected to it, so it knows exactly which port to which the data is to be sent.
In a hub, the data frames are sent to every one of its ports, which places a lot of traffic on the network, and may lead to poor response times.
Routers, however, differ in that their duty is to route packets, which include their destination address, to other networks until they ultimately reach the target.
A router is typically connected to at least two networks, such as two LANs or WANs, or a LAN and its ISP's network. They are located at gateways, the place where two or more networks connect, and configure the best route between any two hosts.
All routers have a Wide Area Network (WAN) port, which connects to a DSL or cable modem for a broadband internet service, and the integrated switch allows users to easily create a LAN. Of course, some routers have wireless access points built into them, and many of them have a built-in, configurable, hardware based FIREWALL, with varying degrees of capabilities for this very necessary protection from the ever increasing number of parasites and malware out there on the web.
Simply put, a hub binds together an ethernet network segment, a switch is able to connect multiple ethernet segments more efficiently, and a router can achieve all of these functions , plus many others as required.
So, in your case, Andrew, a router, be it wireless or cabled, would seem the way to go.
Submitted by: John H.
To answer your questions; A router is a device that interfaces, or connects, your network to the outside world, the internet. A router leases an IP address from your ISP (Internet Service Provider), and in turn allows you to access the internet. An IP (Internet Protocol) address can be equated to a physical address; there can be no two alike. A router can be stand alone, or incorporate a switch, what a switch is, I will explain shortly. The router can be responsible for issuing each computer on your network with an IP address. This is known as DHCP, Dynamic Host Control Protocol. Just like the internet, no two computers on your network can have the same address.
A switch is a device that contains several plug in ports, in order that you may physically connect to it, and in turn, if it is not incorporated into the router, connects to the router. More commonly than not, however, when you purchase one of the mainstream consumer routers, it will have as switch incorporated into it. A switch does much the same as hub, but its a bit more intelligent. What I mean by this is; when a switch receives a packet, destined for your computer, it will send directly to your computer. A hub will send that packet to every computer on your network, until it finds the one it was destined for.
Most of these same routers will allow you to incorporate a third-party firewall product by modifying some internal settings; however, this is usually not required. Windows XP firewall, which was made more robust with Service Pack 2, should be sufficient enough to protect your systems internally. Since your systems are already running Windows XP, they already have a firewall.
In a normal environment, all that is needed is a router, which incorporates a switch, a network interface card for each pc (if it does not already have one) and a data cable for each computer to connect to the switch. If running a cable to each computer is not possible, then I would recommend obtaining a router that also has wireless capabilities. You would then need a wireless adapter for each pc you do not intend to connect with a physical data cable. Be sure that when you purchase your components, that they are compatible. The two most common standards available are 802.11b and 802.11g. 802.11g is backwards compatible to 802.11b, the older standard, but 802.11b is not forward compatible to 802.11g. In other words, if your router is 802.11b, then it will not be able to communicate wirelessly, to an 802.11g wireless interface card.
I hope Ive answered more questions than Ive created. I wish you well in getting your network implemented.
Submitted by: Daniel F.
To Andrew C. of Lawrence, KS, question on Routers, Switches and Hubs:
As far as needing all 3 of routers, switches, and hubs depending on how/where you hood up all 3 machines are they in your home in different rooms, or in an office with different rooms, or in one large office within a few feet of each other? Thats where the routers/switches and hubs come in.
The router is like a gateway with 2 IP addresses one for the network (your machines), and one for the Internet and most routers are sold with two-way broadband Internet access devices [like a 2-way cable modem and fixed wireless broadband services or DSL lines. These then connect to the computer via a 10BASE-T Ethernet port so that is what you need to connect the router to. Routers also provide better firewall protection for all computers on the network if you dont like leaving a computer on at all times to provide Internet access across your network. The best models for routers are Linksys models that can be configured to require networked PCs to be running specified firewall or antivirus protection software before Internet access is granted. Most common routers for broadband Internet access also contain a switch (so you dont need an extra connection device here for your home network).
For hubs: hubs and switches can be used to connect the network and might have some common features, but their differences are also significant and its how you want to use them depends on if you need them. Two types of hubs (passive unpowered, and active used a power supply but both are NOT compatible with Ethernet so, if you have the Ethernet port to use for your router then DONT use a hub. Hubs and switches are similar in that they connect computers on a UTP-based Ethernet network (all 3 of your machines, for example would need the UTP-based Ethernet network in order to network with each other). But instead of broadcasting data (whatever one computer inputs data into, another one picks it up), to all computers in the network hub, switches use a feature called address storing it checks the destination for each data packet and sends it directly to the computer its intended for (sort of like a telephone call makes a direct connection between the originator of a call and the receiver). So, if youre going to use your computers in that way then, yes, youll want both hubs and switches. There are some less expensive hubs and switches for your use and those are that run at only a single speed and have only a few RJ-45 connectors (that is what you need to connect your hub and switch with) some dual-speed hubs/switches are for adding a Fast Ethernet (100Base-TX but those are expensive) clients to an existing 10Base-T network, youll need a dual-speed hub or switch to connect the various types of Ethernet together.
If youre connecting a small network (your 3 computers), you may need a four-port hub or switch (the smallest available). But if you only buy a hub or switch with only 4 ports and want to add more to your network, youll have to add a second hub or switch or replace the hub or switch with a larger one with more ports. It all depends on how many computers you want to hook up together will tell you what type of hub or switch you will need.
Hope this helps you out.
Submitted by: Carlene
Your question is one that network designers have to ask a lot. Your choice of network design is one that will either make you happy or miserable for a long time. A lot depends on your layout. Are all the PC's going to be in 1 room, or several adjacent rooms, or widely spaced, or even on totally different floors of the building? Do you want to wire your home, or go wireless? Might you one day want to share a printer among the PC's? Having a network allows you to do more than just share an internet connection.
First, let me say that Windows XP allows you to share an internet connection by directly wiring your computers together without having a formal, switched network. If all you want is a shared internet connection, this may be the way to go. You will have to buy & install extra network cards on 2 of the PCs, so that you can pass through from one to the other. Total expense: the cost of 2 extra ethernet cards (internal or external) & 2 extra ethernet cables to connect them. You can set the PC connected directly to your dsl line as the "server" & connect the other PC's to it in "series" 1 to 2 to 3. "1" will be the server for "2" and "2" will be the server for "3". This works best if they are all close together, less than 25 ft. (50 or more is possible, but less satisfactory). All your PCs will need at least 1 ethernet card for basic network connection. If you go with internal cards and do not have PCs with manufacturer-supplied cards, you will have to open your computer case to install them. If you go with this pass-thru setup, you will definitely have to install the extra card on 2 PCs. So be prepared for that.
However, if you keep one PC in the bedroom, another in the den, & a third in the basement, for example, you will have to properly network them. Hubs, switches, & routers are, at their most basic, just ways to connect all the wires; but they are also much more. To start at the bottom, PCs send their data in packets. Each packet also includes identifying information about which PC it came from, which PC it goes to, how long it is (in bytes), what part it is of the entire transmission (e.g., packet 25 of 380), etc. These packets are transmitted individually & the PC will wait for a response (acknowlegment or
ACK) before sending another new packet. Actual practice is a little more complicated, but this is the general picture. Now to the definitions.
A hub is simply a common connection point, with no intelligence. It just repeats whatever data packets it receives on one port (connection jack) to every other port it has. This means that only 1 PC can transmit at a time, just like a walkie-talkie. Everyone can hear everyone else on the channel, but only 1 person can talk at a time. Two or more simultaneous transmissions will create a "data collision" & everybody has to stop transmitting for a random amount of time & resend the data. With only 2 or 3 PCs this might not be much of a problem; but if you want to do a big internet download, this will slow it down & waste the dsl bandwidth you are paying for. In addition, data can only be transmitted in one direction at a time, which slows things further.
A switch is much more intelligent than a hub. It can synchronize the PC transmissions so that everyone gets a chance to talk at once & the switch will hold the packets for a microsecond & release them one at a time. In addition, it can "learn" where every PC is (what port it is plugged into) and direct an incoming packet to its correct outgoing port. A hub just broadcasts to everybody. Because of this, a switch permits "full duplex" operation, like a telephone. Everyone can send & receive data at the same time. Data is directed to its destination instead of being randomly broadcast & multiple independent "conversations" can go on at once. Extensive networks can be operated on switches only. Switches can connect the devices plugged directly into them & can interconnect in banks to handle lots of devices. But, all they can do is manage an internal network & that network must be homogeneous, i.e., all ethernet or all token ring or all fiber optic. Large heterogeneous networks use bridges to connect between the switches. Your dsl connection box is most likely a bridge. A bridge can only connect 2 adjacent network segments. How do you talk to someone outside your network? Here is where routers come in. They connect multiple networks using common protocols.
A protocol is like an electronic language. It determines what data in the transmission packets look like. Tcp/ip is actually 2 combined protocols; and it is the language of the internet. It requires that each connected device or "host" have a unique identifying IP address, sort of like a phone number on a telephone network. This way, you can find a computer halfway around the world.
All you need to know is its IP address. This is in the realm of the router.
First, a router is also a switch; but it is a switch plus a bridge plus a remote network finder. Where a switch can only create a network, a router can connect between networks. It has an operating system, like a computer only proprietary, & keeps a memory of the devices that connect to it & the networks to which they belong. It is capable of knowing not just where its own direct connections are, but also where their connections are. For example, if you have routers 1, 2, & 3 connected to each other and if computer B is connected to router 2, when it wants to connect to computer A on router 1, router 2 knows to send the packets to router 1 and not router 3. It can even learn that router 4 is beyond router 1 and router 5 is beyond router 2! Thus, routers can memorize large tables of direct connections & accurately send data flowing over long distances & between different networks.
Home routers also have additional functions, some of which are also carried out by computers, such as dhcp server. They can have a WAN side (router) that goes out to other networks & a LAN side (switch) that connects to an internal network. They can be dhcp servers & Network Address Translation (NAT) devices, which assign private IP addresses to the computers inside their networks, and show a single public IP address to the rest of the world. They can be equipped with a hardware firewall to block unwanted intrusions into your network; and they can be joined in subnets if you should want to separate your internal computers for privacy. Most of the newer home routers are also programmed with PPPoE protocol to automatically log on to a dsl isp automatically. (A short aside about the firewall function. It is always better to still have a software firewall on your PC for maximum safety.)
If you want a home network, you can go with a switch, but one PC will have to have PPPoE software installed for the dsl connection & be set up as the "gateway" to the dsl network interface that your isp provides to you. It will have to handle all your internet traffic for the other 2 PCs, with the consequent performance hit. This means it will always have to be available to service the connection. You will also have to set up manual tcp/ip on each PC & learn how to assign IP addresses. A dsl capable router, on the other hand, will not cost much more than a switch and will be a gateway, an internal swich, a firewall, a dhcp server (so you don't have to manually input tcp/ip parameters on each PC), and a conduit to a printer, with a small additional print server box. If you get a wireless router, you don't have to run connection wires through the house & you can place your computers anywhere within range.
However, you will have to learn how to set up wireless security or you will be broadcasting your network to all the neighbors.
Getting back to your home layout, depending on where & how far apart your PCs are, you can mix switches & a router to extend the network range or just go with one component. I recommend the router because of all the other benefits it can give you for, maybe, 5-10 dollars more. When shopping though, be carefull reading the specs. I have seen components labeled switch/router, which is confusing but true, or access point, which can mean either switch or router.
If in doubt, ask a salesperson for some technical help deciphering the box, or take the model number & reseach reviews on the internet.
I think, once you have the network, you will find so much more to do with it besides just sharing an internet connection.
Submitted by: Loretta L. of Brooklyn, NY
Andrew, let me try to clear up some of your confusion.
Switches and hubs both connect multiple devices together on a network so that packets (messages) sent by one computer can arrive at the destination computer. Since they do the same thing, they are interchangeable. However, hubs send every packet to every computer on the network, while switches send packets only to their destination. Thus switches are more efficient and increase the effective bandwidth of the network. Since switches are no longer more expensive than hubs, there really is no reason to purchase hubs these days. One switch (or hub) with 3 (or more) ports would serve an entire 3-computer home network.
This is all that is required for a local network, not connected to the internet. Simply connect each computer to a port of the switch or hub. However, putting a network of multiple computers onto the internet requires much more functionality, you need (among other things) a DHCP server, a gateway and NAT (network address translation). This additional functionality is commonly provided by a single router connected between the Internet (cable or DSL modem) and the local network (switch or hub). Routers also have some degree of protection (firewall) built into them, but the exact extent and nature of this varies considerably from model to model.
Since this configuration of a router and switch is so common, for home use the two devices are normally purchased as a single unit in one box, sold as a slightly misnamed router. Similarly, wireless routers are actually Wireless Access Points, routers and switches in the same box. [All of these components wireless access points, switches and pure routers are also still offered and sometimes appropriately used as separate products in separate boxes.] While for convenience these combination devices have become predominant, they are still logically separate devices, and in configuring a network it is often necessary to deal with their functionality separately, even if they all reside together in the same box.
In your case, for a wired network of 3 PCs connecting to the internet over a single DSL connection, what you need is a DSL modem, a router and a switch. Most likely the ISP (internet service provider) will provide the DSL modem, and you will get the router and switch as a single combination device. If any of the computers to be connected to the internet are to be connected wirelessly, then you need the added functionality of a wireless access point, which is most easily obtained in the form of what is now commonly called a wireless router. Sometimes, you may run into combination devices that also put the DSL modem into the router, which might be called a DSL router, but most commonly the DSL modem is still separate.
Since you are using DSL, there is one more added wrinkle to be aware of. DSL usually uses a connection protocol called PPPoE (point-to-point protocol over Ethernet). This requires a PPPoE client, a function that was usually provided by the device connected to the DSL modem (either the single, non-networked computer, or the router). However, some DSL modems now incorporate the PPPoE client and a very simple rudimentary single port router (with or without NAT) inside the DSL modem itself. This leads to a lot of possible configurations, a dozen or more, and you may need to get local assistance to configure your network. What Id recommend is first trying it yourself, initially in a simple single computer configuration (DSL modem to computer, no router). Then, only after that is working, try inserting the router between the DSL modem and the computer. If this works, you are home and can connect the other two computers to the router. If it doesnt work, you will probably need to get some local help in properly configuring your home network to connect to your DSL modem and service provider.
Submitted by: Barry W. of North Canton, OH