LinuxQuestions.org - Router vs hub vs swtich?

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OK, I really understand now

When I got home from school today I read the whole artical on switches, and read
the first part of the router documents on howstuffworks.com

A router is something used to connect to your ISP, or to connect networks (switches) together.
A switch is used to connect computers on a lan together
A hub does this to, but from what I read about hubs, I decided to exclude this from my
network plan.

See, now that I know how all of these work, I'm going to redo the network in my house, I'll just
have to get an extra $100 for switches, but I'm selling my wireless router on ebay, for a WAP11.
This is what it's gonna look like-

[cable modem]--------------[router]
| \
[WAP11]---------| \------[switch(5 ports)]-----[node3(W2k, laptop)]
/ | \
|--------[switch (4 ports)] / | \
| | / | \
| [node4, linux]-------/ | \-------[node1(w2k, desktop)]
| [node2 (WXP, desktop)]
[node5, linux]

As you can see, node5 willnot have internet connection. node4 and node5 are my webserver,
and they are clustered. Node4 is also my personal desktop. There is four ports on the switch with the linux computers, and 8 ports on the switch with windows computers because I will probably expan this one day. There is supposed to be a limit of three computers connected to the internet, but how can they tell, if I have a router? :)

All of the routers will probably be linksys or d-link, since they are good and d-link are cheap.
I wouldn't mind getting suggestions on how to imporve this, that would be liked. Node4 allready has a WMP11 in it. I already have the router, it is a router/switch. Its a BEFSR41. The switches I may buy are EZXS55W, since I can get them of EBay for like $15. And then, the WAP11, I can get off amazon for like $40.

Thanks for all of your help though, now I can plot my network out with ease! :)

-Jim

Your comments are welcome, I wouldn't be surprised if this ended up with 30 some replys.

sorry about the half of the post, I pressed somthing that started to load the next page!

-Jim

Interesting, you seem to have mostly figured it out even though no one answered your question...

> what would a WAP11 be considered?

A WAP is exactly that, a "Wireless Access Point" and nothing more. It is not a router, it only
gives you a way to connect wireless devices to your network!

See this diagram: http://www.linksys.com/support/displ...rid=157&scid=7

If you plan on using a WAP11, you'll definitely need to keep the BEFSR41 to do the routing chores.

You mention you already have a wireless router that you are going to sell in favor of a WAP.
What's your reasoning for this? A wireless router is basically the same as a router and a WAP
in one. If you wanted to put your WAP in a different location in the house than the router, I
could see wanting seperate components. Other than that there probably isn't any advantage
to seperating the two devices.

I tried to figure out your network diagram, but it's too botched. If you could fix or re-post,
it would help greatly in trying to understand your network plans...

/Les

just don't want two routers

I just don't want two routers. Also, my routers tend to "shut off" every 3 days, and it happened after I brought the wireless router into my network, so now I'm selling it for a WAP11, hopefully with better
luck.

Here is a more simple version of the diagram-

[cable modem]
|
[router]
|--[WAP11]-------[node4, linux]----[switchb]--------[node5, linux]
|
|
[switch a]-------[node1, windows]
|----[node2, windows]

If you noticed, there is a node missing, node3. Node3 is a laptop connecting to switch a, but it's not always present and requires the use of VPN, so it can connect to it's VPN server, it uses windows.

If I had two WAP11's, could I do this-

|
[router]
|--[WAP11]-------[WAP11]----[switchb]------[linux machines....]
|

Where [linux machines....] is node4-5, and if I add more nodes to my cluster. But, could I have two WAP11's, just to act like a wireless bridge, even though this is what a wireless router is for? See, I don't want to use a different router since my current wired router has a DynDNS client in it, and I like that. But I would like the windows computers to be able to communicate with node5, and switchb, without setting up a router on node4.

So, any suggestions? The switches that I will be using are the Linksys EZXS55W, they are five port
switches, I can get those of ebay for a nice price. Unless someone knows of a better switch, I looked at the Linksys SD205, I may use those instead.

-Jim

As far as I know you can't use two WAP11's together to act as a wireless bridge.
For that you'll net a WET11: http://www.linksys.com/products/prod...id=602&scid=36

[WAN]
|
[router]----[WAP11]~~~~~[WET11]----[switchB]----[linux machines....]
|
|
[switchA]----[windows machines...]

<or>

[WAN]
|
[router]
|
[WAP11]
~
~~~~[WET11]----[switchB]----[linux machines....]
~
~~~~[WET11]----[switchA]----[windows machines]

Note: A wireless bridge is not a wireless router. A bridge is just a way to get a signal to a remote location.

The only router in the diagram is the BEFSR41.

As for a switch, I really like the Netgear FS105: http://www.netgear.com/products/details/FS105.php

Also don't forget the BEFSR41 has a four port switch built into itself so you could use it to connect machines
directly to it as well...

/Les

There are lots of good explainations in this thread for technical definitions but what you need is to get past the "marketese-speak" that is on the product labels. A wireless access point (WAP) is by it's nature a bridge, it "bridges" the wireless network to your wired network. If it has more than one port then it is most likely also a switch (to oversimplify it, a switch is a multiport bridge) If it has functions to do NAT so that you can use it to share networking they usually call that a router, although it's a lot like a gateway and is sometimes called that too.

So as for what you want, it sounds like you want a WAP, which may be labeled a bridge, but the ones that aren't explicitly labeled as bridges are anyhow. If you get one that has more than one wired network port, it should use switched ports (meaning the wired network part is like a switch, not a hub.) and this may also be on the product info label somewhere. If it lets you share your internet connection it's usually also labled as a router or gateway, it should also have NAT listed in the technical fine-print somewhere.

You should get the device you need for your network. If you want just a wireless acess point, those are fairly cheap. If you have more than one computers on your network you may also want one with more than one network port, then you can replace any hubs or swithes on your network with a new device that does their job and adds wireless. If you have an Internet connection that is a network attached device like a DSL router, most of the new ones do the NAT thing already so you don't really need your WAP to do this, but they usually don't cost more, and some are cheaper because of popularity, so it doesn't hurt to have this feature in case you change your Internet service to one that doesn't (or the ISP changes it.)

As an example to explain above, Linksys has a WAP54G (54MB wireless G version of the 11MB wireless B WAP11) which is a simple wireless bridge with one ethernet port. Their WET54GS5 appears to be a Wireless switch, it's just a WAP54G with more than one ethernet port. Their WRT54G (or BEFW11S4) throws in NAT, and is proably more popular, and cheaper, than the WET54GS5 even though it does more. This last type of device can also sit behind DSL or Cable-Modem or a Linux firewall to share your one public IP address with your whole network. Some of them can also have the NAT turned off and be dropped into 'bridged' (switch) mode. Devices like their WCG200, if you ever switch from cable-modem or move to where it's not available, can easily become an expensive, dust collecting, conversation piece. Avoid those and rent your access device (cable/DSL) from the ISP since it will probably be obsolete before you would have bought it anyhow.

OK, WET11's seem pretty cheap, I'll probably buy one of those. I'm at school right now, so I can't make a new diagram.

-Jim

Darin brings up some good points. Although, I would be careful with trying to use a WAP as a BRIDGE and
vice-versa. It's not that these devices are not capable of acting like the other, but the manufacturers don't
include the functionality in the device (for the simple reason that if forces you to buy more hardware).
Always verify on their website that the device will do what you intend.

I had thought also to mention the WET54GS5 in lieu of the WET11 in my previous post, but didn't want
to confuse the issue. Since 802.11B and G are compatible, it should work. The WET54GS5 is a Wireless-G
Ethernet Bridge with 5-port Switch built in: http://www.linksys.com/products/prod...id=35&prid=615
If you use it with a WAP11 it will just drop down to the B speed. The main issue here is price. The WET54GS5
will run you around $150+ since it's a fairly new device. Whereas a WET11 can be had for less that $50
on ebay. So the cost of a switch together with a WET11 is far less than the cost of the combined device.

NOTE: If you have an 802.11g network and you connect an 802.11b device, the network will drop down
to the lower connect speed (and all of the attached devices will then operate at the lower connect speed).
Theoretically once you remove the 802.11b device from the network it should return to the 802.11g
speed (although I haven't verified that).

/Les

That's one reason why I didn't select wireless G for my network, it's expensive. A lot of wireless B parts can be bought for less than $50, that is, for homenetworking. When you go to buy one of those industrial strenght wireless points for say a large office, or for like a school/college, they probalby cost
more. By the way, who sells those, a wireless access point that can handle possibly thousands of wireless connections?

Anyway, while I was at school, I took in consideration what Darin and Linuxles said, and this is possibly
what my network will look like now-

[cable modem]-----[router]
| |
[switch]--[WAP11]~~~~[WET11]
/ | \ |
/ | \ |---[switch]
[node1]-----/ | \---[node3] | |
[node2] [node4]---| |--[node5]

Hopefully, that won't get messed up. Node4 and node5 are linux. Any more suggestions?

-Jim

Hello again-

Could I uplink directally from the switch to the WAP11? Like such-

[router]
|
[switch]-----[windows computers, node 1-3]
|
[WAP11]~~~[linux, node 4]-----[switch]-----[linux, node 5]

IF so, I may buy one of those single port routers that are used for routing only and not
switching, since they are probably cheaper, I could sell my current router, to buy
more switches/other networking equipment. I'm also going to take a look at netgear
routers/switches, etc.

-Jim

That looks a lot like my home network, although I'm using an 802.11G bridge pair between floors vs the 802.11b you have specified. I use both netGear and Linksys. You just missed a deal at Office Depot with the LinkSys 5-port switch at $9.99, you might want to take a while shopping around to see if another such deal shows up. I'll attempt to stick-figure my network here but I know the formatting lacks so I'll do a line per network device or two so I can outline the full extent of the equipment:

CableModem -------- Router/4port switch (this connects to Switch1, VPN-Router, Switch2/PrintServer)

Switch1 (Linux (VMWare with RH, SuSE, Win98 virtual machines), WinXP, Win98, Win98)

VPN-Router (8-port switch with connections to: VMWare (3 Win2000, Linux, and 2 Winserver 2003 virtual machines), Win2000

Switch2/PrintServer [Main floor in house] ( WinXP, 802-11G Bridge-a, plus printers)

802-11G Bridge-b (XP-GameMachine, XP, OS-X)

FYI, I'm a Network Engineer plus I test pre-alpha software on various platforms, my wife runnings a home based business, my son and I are gamers as well.

So another view of the network in terms of just the ethernet segments would be:

{=======Internet=======ISP is providing an additional firewall===}
|
Cable Modem
|
Router (minor firewall)
|
-------------Home Ethernet-------/\/\/802.11G bridge\/\/\-----------
|
|
-------Secure VPN Network-----------

If I understood your drawing, your network look similar to this. I've had absolutely no problems with my network and I've run quite a bit of traffic on it as well as many network protocols like IPX and AppleTalk besides IP. I am thinking about putting in an additional router with stronger security to connect directly to the existing router/switch and place the Linux server between the two routers, thus creating a DMZ between the Internet and the home Lan.

As you have indicated, 802.11b will meet your home needs quite nicely. I pass a lot more traffic then most home users including Voice, Video, and simulated network traffic. Internally, the slowest link is 100Mbs but the wireless 108Mbs is really somewhat slower due to it being wireless....

There are some things to be aware or with wireless:

1. It works more like a hub than a switch, in your reading it might have talked about 10Base-2 or thinnet, collisions, etc. Wireless takes your network back to those days with a few extra collision framing issues that did not exist on 10Base-2/thinnet/thicknet.

2. Someone alluded the speed issue when talking about 802.11G with a 802.11B device. The whole network slows down to the slowest need. But the slowdown goes beyond the "G"/"B" issue. Assume you have 3 laptops on 802.11b, of the 3 laptops 2 are in the same room as your WEP and normally enjoy fantastic connectivity to the local server. When you turn on the 3rd laptop located in the bedroom you find this computer as well as the first two laptops now have poor performance. The 802.11 devices have a bandwidth step-down they go through based on the packet re-transmittion frequency. If a device is at the fringe of your wireless transceivers radius, it is quite possible your wireless system is running at the lowest rate of 1-Mbs. Metal buildings or metal positioned in exactly the wrong place can create a radio-frequency multipathing condition that can cause a higher rate of re-transmissions making the network under-perform. Do you have 2.4 GHz cordless phones or other 2.4GHz devices that can cause interference? If you have a lot of 2.4 GHz activity near you, you could move to 802.11a (i.e. to 5-GHz) but your cost will increase and the operating radius will be reduced. The operating radius will be reduced because 802.11a devices are not permitted to have anything other than built-in low efficient antennas.

Other discussion about what a /hub/bridge/switch/router are (based on ethernet; ignoring how the devices learn):

Hub: Interconnects devices in a single broadcast and single collision domain. Which means every device on the LAN segment receive and process all broadcast messages and only one device can "talk" at a time. If two devices try to "talk" at the same time, this collision is detected and they will try to talk again a little bit later.

Bridge: Interconnects devices in a single broadcast domain but separate collision domains. Therefore every device will have to process the broadcast (like on a hub) but the collisions will be less frequent because not as many devices are on the same wire (LAN segment).

Switch: Generally the same as a Bridge but with a single device connected to each port. Therefore each port is its own collision domain. This then opens up the communication to full-duplex ("talk" and "Listen" at the same time)

Router: Each port is a new broadcast domain and a new collision domain.

The switching function is generally programmed into the ASIC (as previous post said) and is very very fast. Sometimes when you read the marketing idiots stuff they will double the port bandwidth to indicate full-duplex (instead of saying it is a 10Mbs Full-Duplex port the may call it a 20Mbs... that sort of thing).

Routing is more of a software function. The router looks to see the best path to a distance destination (which might be half-way around the world or directly connected). A router can provide some form of network security, but are not strong security devices.

I think I likely overstepped what you wanted.
:rolleyes:
Anyway I hope this helps somewhat.

Dan

Hubs are pretty muchly passe. The term is often used now in a generic way, though. If you can get a switch for a good price, go for it. Twice, I have bought 4 port Fast Ethernet (100 MBPS) switches for $4.99 each, brand new from MicroCenter. I shop on the internet, too. Of course, you can expect to pay more unless you luck onto such deal. If you want to share a broadband internet connection, you will need a gateway-router. I once bought a D-Link 704P (with 4 Fast Ethernet ports) for $19.99. It does everything all by itself, so I don't need a switch or any other unit. I had previously paid $40 or so for a 704P. The 704P does not include a wireless access point, so if you need wireless, you will need a similar unit that also has a wireless gateway. Of course, that will require a wireless interface for each computer that uses wireless connection. Also, wireless access can have problems with range and interference and possibly with security.

Side Note: My Sprint/Earthlink DSL modem has a single port router built in. I had to "bridge" (i.e., defeat) the built-in router before I could use the D-Link gateway. The instructions were on the Sprint DSL web page.

Comment: Some of the other comments people have made sound like they came out of a textbook or dictionary. I have taken a course in networking, but, for the most part, you need practical up-to-date advice, not networking theory which ignores the changing face of technology and the fact that certain technology that used to be very expensive has become very cheap.

I suggested the wireless access points that come with the switch built in because the idea seems to simplify the network. It combines the function of what can be two seperate devices into one unit, less wiring and power plugs needed. It also has a small performance benefit where the wireless network communicates with the wired network using the higher speed of the wireless switch's backplane (it's intercommunication between all the ports works at a speed that is faster than the individual ports so a 100MB switch can handle more than 100MB total since each port could use 200MB, or 100 each way, and the switch needs to handle that speed on multiple ports) rather than the single uplink line connecting the switch to the WAP. It also appears that the wired switched ports that they add to wireless devices could be of higher quality than one of those $4.99 switches.

Think of this as a room analogy where each device: hub switch, WAP or router, is a room and the wires between them are doorways. For the devices on the wireless to talk to wired devices they have to talk through the door (uplink port) and to get to The Internet they have to talk through two doorways and through the other room (the WAP wired to the switch wired to the Internet gateway) where as a WAP with wired ports is like one big room where devices just talk to each other in the same room and only have one doorway to go through to get out to The Internet.

The Linksys wireless-B device BEFW11S4 is a WAP with built in 4-port switch (also a router, but that could be disabled if you don't need that function of it) and this shouldn't be much more than a plain WAP11. It could also be cheaper to get than a seperate WAP and switch, depending on how cheap of a switch you get.

I agree with Darin 100%. That's what I was using until the transmitter on the Linksys failed and I was forced to change to something else. At about the same time as the linksys transmitter failure we decided to move some computers around making a wireless bridge an optimal solution. The office in the basement and the main floor are now fully wired with cat-5, but picking up my son's room with cat-5 would have been a real pain!

Also, if the transmitter on the Linksys was still working, I don't think it would have worked well for the distances and number of walls and floors. When the Linksys BEFW11S4 was working it had a difficult time making it through 1 floor and wall for a distance of about 20 feet. Maybe the newer ones are a bit stronger then the older ones, they might now allow the signals to pass though a wall or two without as much packet loss.

If you can avoid using wireless and use cat-5 for everything I think you'd have less neting issues over time. But there are situations that make wireless really nice! My wireless bridge has been trouble free. And I really like the wireless (non-bridge) for the laptops so I'm not hooked to a leash and I can actually work from the deck using 802.11b and a wireless phone (not a 2.4G phone though, that gave me some real problems).

What you had listed would work fine. But what Darin said makes a lot more sense. If you are not going to do a long wireless run, I think you'd be happiest with his solution.