Second Setup

[JCDyer]

Ok... I have gotten all the cables and equipment I believe I will need. If I can not get this working I might just setup linux as my router, like someone in my previous post stated. I just did not want to do that due to the fact that my linux box is VERY old(cyrix 166).

Anyways... My new setup is like this:
................................[Linksys Cable Modem]
.................................................|
......................................[Linksys Router]
......................................../....................\
......................................./.......................\
....................................../..........................\
.....................................|............ ................|
................................[Win 1].............[Netgear HUB]
.................................................. ......./...................\
.................................................. ....../......................\
.................................................. .....|........................|
..................................................[Win 2]..............[Linux]

Ok... So that is how I have it configured... With that setup niether Win 2 or Linux are getting internet. Win 1 is working fine though. Do I have to plug the HUB into the uplink port on my router? Or just in a regular port? Also, does the HUB have to have the Uplink button pushed in, or should it be set to normal. I have tried all combinations with it, but still could not seem to get it working. Cables are good, power is connected... Win 2 works fine when I connect it to the router, Linux still does not work when I connect it to the router.

Anyone have any ideas why this new setup could not be working? It sounds like the easiet way to do everything would be to just use Linux as my hub, but then I have lots of wasted equipment here(Router, Hub, Cables). Plus the fact that linux machine is old, not sure how stable it would be to be constantly running.

I appreciate any help you all can provide, and thanks a lot for the help so far.

JCD

[JCDyer]

WHO HOO! Finally got internet working on my linux machine... Granted, it is not setup the way I want it to be, so it is not much use to me(It's connected directly to my router)... But it is somewhere. Now I just need to find out why niether my windows machine or linux machine will get a connection when they are connected to the HUB. Does anyone have any ideas, or can anyone point me in the right direction. Agian, I would like to stay with the setup in the diagram above.

[michaelk]

The uplink button switches between a crossover cable and a straight cable on the port. Are the link lights illuminating on the ports that connect between the router, hub and PC. If not then you probably have a cabling / switch issue.

[JCDyer]

The ports for the Windows machine and Linux machine on the HUB are lighting up. The connection from my router to my hub is not. Do I need to do anything special to connect those two?

[michaelk]

If you have a straight cable connecting the two then don't use the uplink port on the router. Use a regular port on the hub or deselect the uplink button on the uplink port. Check the documentation on the router and hub.

When you get all of the links working you should be able to ping the router from either windows or the linux PC.

[IsaacKuo]

With your Linksys router, you want to plug the hub into the uplink port, and set the "uplink port" button on.

This is assuming you are using all normal cables. If you have a crossover cable somewhere in there...well, it's a bit messy. You probably don't have a crossover cable anywhere in there.

All the "uplink port" button does is switch the port between crossover and normal mode. It can be a bit confusing, but think of it this way:

Crossover cables go between:

Computer<->Computer
hub or switch or cable modem<-> hub or switch or cable modem

Normal cables go between:

Computer <-> hub or switch or cable modem

Roughly speaking, there are two sorts of devices, Computers and "everything else". You use a crossover connection to go between similar devices; you use a normal connection to go between different devices.

However, something like a network printer or network drive looks like a "Computer" to the network. Think of it as a primitive "Computer" with the printer or drive acting as a server sharing its device over the network.

The router is an unusual case because it has two sorts of ports. One is the port to the cable modem, which acts like a "Computer". That's because it's essentially taking the place of the Computer, as far as the cable modem is concerned. The other is all of the switch ports to the internal LAN. On these, the router looks like a hub/switch.

The "uplink" mode button just swaps a couple lines in the "uplink" port so that it looks like a "Computer". Thus, a normal cable can be used to connect it to a hub.

Incidentally, if you crossover a crossover, you get a normal connection.

[IsaacKuo]

BTW, the reason why we have crossover cables and normal cables is due to the way this flavor of ethernet works.

There are four lines. Two of them are ground, and don't carry any signal. The other two are (normally) an "input" line and an "output" line. They carry data, but they're like 1 lane 1 way roads. Now, if both of the devices on both ends try to use line 2 as "output", then it just won't work. Both will output to that line, and no one is listening! So it's important that one side treats line 2 as input while the other treats line 2 as output.

That's what happens in a normal cable. With a "crossover" cable, the input and output lines are crossed over, so it will work if both devices use line 2 as "output".

You might be thinking, wouldn't it have been nice if they just decided early on to use only crossover cables to connect everything?

Well, you'd be right, if everyone used nothing but prepackaged cables. In reality, most serious networking is done with cabling cut to length and hand crimped. A "normal" cable is a whole lot easier to put together right, when the other end of the cable is halfway across the building. With crossover connections, you'd constantly be going--okay, so is this the end where Green goes to 1, or Orange goes to 1?

(Note that there's also "full duplex" where both data lines are used in the same direction. Both of the devices have to support full duplex for this to work, and this doubles the speed in one direction. This is like taking a two lane road and converting it from two direction traffic to both going in one direction.)

[michaelk]

Isaac Kuo

If you want to be technically correct ethernet wiring is 4 twisted pairs. 2 of the pairs are not used. The other two pairs, one pair is used for transmit and the other is used for receive. However the signals are not single ended i.e. one wire grounded but a differential signal. TX+ has positive going pulses and TX- has negative going pulses. The signals are combined together in a line receiver integrated circuit.

If it was a single ended circuit the lenght of the cable would be limited to about 50ft instead of 300ft.

[IsaacKuo]

Cool, I didn't know that! I don't quite understand it, but then I majored in Computer Science and not Electrical Engineering.