8/27/05 Routers, switches, and hubs, oh my!

Hi Gary -

Your CNET answer was very timely and most informative. Thanks!

I use Win 98SE with an HPNA (Home Phoneline) network for 3 PC's. I would like to add a print server for an HP 970 CSE printer. Can I simply plug the print server into my Linksys router or do I need some extra bits and pieces to make it work properly?

I would appreciate your advice.

All the JetDirects I've worked with lately come preset to use DHCP/BOOTP to get an IP address. All you should have to do is connect the JetDirect to the Linksys and then connect the power (or just turn it on if it has a switch). Once it's booted, you can use the JetAdmin software to fine tune the configuration.

Gary, your answer is well taken. I have learned a lot. But I have a question. I have one desktop and two laptops connected to a router. I am trying to share one printer among these three computers. In most cases I am not able to do so. Your response is making me think that may be a switch will be helpful. Can you tell more about this? That is how to go about sharing a printer among 3 computers. All computers are windows xp. The two laptops are tosheba and ibm, the desktop is hp and the router is netgear.

Thank you.

Assuming that you have the printer attached to one of your computers on the network and that your network is set up correctly....

You will need to set up printer/File sharing on the computer with the printer. Control Panel/Printers and Faxes, right click on the printer in question and select Sharing...

At this point Windows will warn you about sharing usually. I tell Windows that I will set up the sharing myself. On the sharing dialog, select "Share this printer" and give it a name. This should allow the printer to be shared.

On the other computers, then, Go to Control Panel/Printers and Faxes.

Select Add a Printer.
The wizard will start with an info dialog, press NEXT.
The wizard will ask Local or Network. Select Network and Press NEXT.
The wizard will ask Specify a printer. Select "Browse for a Printer" and Press NEXT
The Wizard will browse for a printer on the network. The dialog is in a tree style display showing the network workgroup name at teh top with the attached machine underneath.
Find the machine with the printer and doubleclick on the machine if you need to. Then select the appropriate printer noted under that machine and select NEXT.
The wizard will make sure you are sure. Click YES.
The wizard may ask if you want to make the printer the default. Answer appropriately. Click NEXT.
The Wizard will note its completion. Click FINISH.

Voila, you have a printer shared to another computer.
Happy printing.

Chris

i think Chris has answered the question for me. what he says is correct.
gary.

Let's say in the near future I am looking to connect my PC, a laptop computer, and a game console like PS2 or Xbox to a wireless network on a cable internet connection. Does the same broadband solution apply? Do you need both a wireless hub and a wireless router? And are there significant differences in different brands of each, or will the cheapest one do? I'm new to all of this and would appreciate a simple answer. Thanks.

A wireless router almost always comes with a built in switch, and it is also an access point. So basically you would just get a wireless router and plug it into your broadband point or telephone jack. being an access point it would give off the wireless signals too.

your computers would probably automatically detect the presence of the wireless network. the manual should guide you through any configuration or hitches.

a wireless router is definitely the simplest solution.

Gary.

I have 2 computers networked (hard wire) together and can have either or both connected to the broadband (cable) internet. If I buy a laptop, what do I need to bring it into the present network? Should I buy one wireless router and hardwire to existing computers in place of present router? and then wireless to laptop?

If you want to connect to the network wireless, you will need a wireless access point (in case your router doesn't already support wireless). You then connect the access point to the router using a cable.
Or, alternatively, buy a router that DOEs support it.

If however you don't mind messing around with cables, you can just connect your laptop directly to the router hardwired.

Then it's just a matter of giving the laptop an IP address in the same range as the other PC's and configuring it with the same workgroup name.

Gary's reply was accurate, but long, and I have to confess, I didn't read it in detail.
The short answer I would give - look for a router that has a switch built-in. Most of them have at least three ports. That will let you plug in all three computers, and you won't need a separate switch or hub. You can add a switch at a later date to add more devices if you need them. If you decide to go wireless, that will let you connect laptops and other wireless connections, but it has another set of terms that complicate matters. Some manufacturers are trying to simplify it.

I would also suggest that you make sure that the firewall you use incorporates NAT (Network Address Translation). In a NAT firewall the external address is different to the ones used internally so a computer on a Class C network with an address of 192.168.x.x is not seen on the Internet at all as the address is translated to an address the router uses. Most wireless routers that connect to the Internet with an internal or external DSL modem incorporate a NAT firewall.

The other thing I would suggest is that when you complete your setup, goto www.grc.com and run some of their free utilities. Shields Up is a good one for showing how exposed your machine is to the Internet. It probes for remote access to your machine through the first 1,000 ports and gives you a full report.
Finally don't forget that last essential on all your machines.... a good anti-virus package (I would recommend AVG 7 Free version)

i agree with and support the NAT idea since it enhances safety by creating an IP address different from the computers on the network. for an office network with security risk this is recommended.

However most firewalls do an adequate job of hiding your ip address anyway so for a home network you may or may not want to go in for NAT. its just additional protection.

Gary.

I have multiple (3) computers running through a Linksys Wireless G router (all hardwired) without the use of a hub as you suggest. We do not share info just the internet connection. (cable) Does the Linksys router have a hub built in? Great article!
Thanks,
Rich V

I am aware of similar situations as yours in the case of wireless networks. All you need is a wireless router and youre set. I seem to have totally overlooked wireless products in my article although I had meant to put a little info on them in there, so must have slipped my mind.

There are many router+switch (2 in 1) products available today for non-wireless networks.

For wireless networks, most routers come with a built in switch.

I looked up the linksys products page
(http://www.linksys.com/servlet/Satellite?childpagename=US%2FLayout&packedargs=c%3DL_Product_C1%26cid%3D1115416939789&pagename=Linksys%2FCommon%2FVisitorWrapper) and it looks like every wireless router they have doubles as a router and a switch (and also as an access point). So yeah, you dont need the switch/hub coz you have one built into the router.

Your's is probably the most convenient setup.

Gary.

I would like to know about subnet mask. In case of three or four computers in a home network how is the subnet mask configured? What is this actually? My comuter connected to the internet through a cable modem always shows subnet mask as 255.255.255.0 even though the IP address keeps changing every session.Quite confusing for me.

Subnetting is a little complicated. The subnet mask sorta defines whether the network is a class A, B or C network. In fact if two computers have identical ip addresses, but different subnet masks, they would be on different networks. However I didnt talk about this in the article as it would really confuse a lot of people who will never really need to know this stuff.

It would take a lot of time (and typing for me) to explain subnetting so im gonna link you to a few websites that will teach you how to subnet:

Heres one that offers free video/audio tutorials:
http://www.learntosubnet.com/

Another good one
http://www.ralphb.net/IPSubnet/

Some others:
http://compnetworking.about.com/od/workingwithipaddresses/l/aa043000a.htm
http://www.semsim.com/ccna/tutorial/subnetting/subnetting.html

Gary

Thank you for one of the most lucid examples of technical writing that I have ever seen. Would that all tech support operations approximate its clarlity and thoroughness.

thanks for that

Wow. Great job. Real talent for teaching.

gee thank you.

This is the best answer I've ever read in these forms.
Great Job...

thank you :-D

Excellent reply except for one thing you mentioned that for a high speed connection that individual needs to buy both a router and a hub/switch although this is technically correct most major manufactures have what they refer to as access points. What they are is a combination router and hub and are specifically used to connect a DSL or cable modem to an internal network and interconnect all the computers. Their are also wireless versions of these devices as well. What these devices accomplish is the router portion for sending and recieving data from the internet, but they also allow internal data transfer between computers. Whether buying both a router and a hub is less then the combination access points I'm not real sure but it one less box to have around.

you're right. many other posters have mentioned the same thing. router+switch in one devices are the best choice. im used to thinking in terms of giant networks rather than small home ones so i was going by theory.

never before had i seen the distinction made between the mac address reading for switches and the IP address reading for routers. that makes so much more sense to me now, as to their application. thanks for putting this in these terms.

Gary,
I am really confused about this particular paragraph in
your post. You wrote:
"Now you might well wonder, why not just replace switches with routers. That is possible in some situations, but not all. What if you had three computers with IP addresses 128.0.0.1, 128.0.0.2, and 128.0.0.3 connected to a router. All 3 IP addresses are of the form 128.0.0.x. If one computer tried to send a packet to the other, the router would think to itself ?The IP address of the destination is of the same form as the IP address of the sender. The destination computer must obviously be on the same network. I should not allow this packet through me?. And so the packet would be blocked off and communication would be impossible."

It doesn't make sense to me unless you are meaning to say that each of the 3 computers would have it's own router instead of a single router with 3 Lan inputs.
Please help me understand.
Thanks.
trent.

see a router always looks at the form of the destination computers ip address. if the source computer of the message has the same form of ip address, it means that it is on the same network as the destination computer.

since routers connect networks, the router would decide not to let this message pass through it since the message needs to remain in the current network (the assumption is that other ports of the router are connected to other networks). so the router would think 'the destination computer must be in the same network as the sourcce computer so it should reach the destination without having to pass through me'. basically the package would travel from the computer down the cable to the router and then the router would block it.

Gary,
Thanks for the quick reply, but I am still confused.
My home network is connected as follows.
2 computers, each one connected to common Router.
The Router is also connected to the Internet Modem.
Both computers access the internet through the Router.
Both computers talk and files can be exchanged with each other..
The IP's are XXX.XXX.X.100 and 101 respectively.
It works great even though they are on the same network.
What am I not getting here ?
Thanks.
-trent-

Theoretically that setup would not work for reasons I've already described.

However since you have only one computer in each port of the router, it might not be associating each port with a certain network type, but rather with just the individual computers. If you had three computers with the same IP address form on each single port of the router, maybe then the problems would arise, because the router wouldnt know which port to associate with which network.

Another possiblity is that it has a built in switch. If you notice, most wireless networks have just one router and no switch because the wireless kind always come with built in switches. Even though yours is not wireless it might have a built in switch.

A third possibility is this (and this might confuse you): the ip addresses might be of the same form, but the subnet masks might be different. The subnet mask is the part that looks like 255.255.255.0 or 255.255.0.0 (or more complicated combinations). Two computers with the same IP address but different subnet masks would actually be on different networks. However subnetting is a complicated topic that you will never need to know, so if you dont understand this, dont worry about it.

In any case, your setup seems to be working correctly. I wouldnt worry about it if I were you. Generally when designing big corporate networks one sticks to the rules and theory takes precedence, because you dont want anything to go wrong. In a home network if something works, I say go with it. Maybe the manufacturer of the router has not followed the internationally defined standards precisely, or maybe you're just plain lucky

Gary.