2 IP's - 4 Computers... ??

on Wed, 01 Sep 2004 03:02:27

Actually you could also get a second router (if I understand what you're trying to do) free after rebate and use that to bridge your two networks if that's closer to what you need to do to test.

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I'm not sure I understand why you need a 2nd IP address.

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A cable modem doesn't do anything but bridge your Ethernet network to the cable lines. The IP addresses don't go to the cable modem. The network servers you connect to give your computers IP addresses; they simply pass through the cable modem.

Reply to
Elmo P. Shagnasty

I currently have Roadrunner cable service. One cable modem connected to a router which connects to my 4 computers.

I need one of my 4 computers to have a different IP address than the others for a program I am working on.

Roadrunner offers an additional IP address for $4.50, cost is not a factor as I need this extra ip.

Question: If I call and get the additional IP, how do I set this up. Someone told me that I would need to connect the cable modem to a hub and from the hub connect one computer to it and the router for my 3 other computers.

Is this correct? I am confused as to how 2 ip's can be sent to one cable modem? Does the HUB know what to do? How?

I have a dlink router, can anyone recommend a hub?

Thanks for your time.

Reply to
Robert Riehl

That is correct. Any hub will do. There's no reason to spend more than you have to.

Why would it be confusing that more than one IP can be behind a cablemodem? The cablemodem is nothing more than a bridge between the Ethernet and the RF cable portion of the network. If there can be traffic for more than one IP on the cable going by your house, serving you and your neighbors, why couldn't there be more than one IP on your side of the bridge between the mediums (Ethernet and RF cable)?

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"Robert Riehl" wrote in news:7ZaZc.28223$ snipped-for-privacy@twister.nyc.rr.com:

If what you need is two IPs from your ISP rather than two IPs from your router, your friend is correct.

If you purchase another IP from Roadrunner, you'll get two IPs handed out by Roadrunner to your modem. Connect the modem to a hub. A 4 to 5 port auto-sensing hub will cost about $20 or $30, and allow you to use all straight-through cables. Most brands will do; this Netgear FS605 will work:

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Connect one pc to the hub, and the D-Link router to the hub. Connect your other three pc's to the router.

Basically, that's it. You're modem is sending two IPs to the hub, and your hub is sending one of those to the pc, and the other to your router.


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FALSE prophecies from the archives, "Robert Riehl" on Wed, 01 Sep 2004 03:02:27 GMT spoke:

Absolutely correct.

The computers will handle getting the IUP addresses, same as if you only have one computer. DHCP does the work.

Any one will work, but a switch is better (think of it as a 'smart hub').

Shouldn't cost more than $20 at most computer stores.

This is at Fry's, $18...

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Again at Fry's, this one is $10...
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Reply to
Never anonymous Bud

Some routers can handle more than one IP and forward them to the appropriate computer. A hub doesn't "know" how to do anything, but pass on packets to all ports. A modem can be configured to handle more than one IP, but sends them out on the same wire, to whatever you have connected to it. So, if you had a hub (or switch) between your modem and router & computer, both the router and that one computer would see the data from the modem. They would only respond to data sent to them.

Reply to
James Knott

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