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Multiple IP addresses, Router question.

Last response: in Networking
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July 15, 2006 7:48:15 PM

Soon, I'll be moving into a new house shared with 4 uni students. The house is currently with Telewest Broadband (the local cable company). The topology currently looks like:

Internet --> Cable Modem --> 16 port switch --> 1 PC.

I'll be staying at the house for a while, so I'd like to add a router:

Internet --> Cable Modem --> Router --> PC + Laptop via wifi.

In the future, I may be switching the houses connection back to BT and use Eclipse ADSL (www.eclipse.net.uk) as the ISP instead, mainly because I've used them at home for years and found them to be brilliant and also because they let you use up to 8 public IP adresses. I'd like this because of the 5 people in the house, 4 of us are heavy gamers and use peer-to-peer a lot and I'd rather not have to bother with port forwarding and NAT address stuff if I can help it. Once everyone moves in, I'd like the topology to be:

Internet --> Cable/DSL Modem --> Router --> 16 port switch --> 5 PCs + 2 laptops via wifi on the router.

We may also add a media server to the switch at some point.

My question (finally!) is whether or not it would be possible to assign each of the 7-8 devices on the network their own external IP address given to us by Eclipse and if so, what router would you recommend to do this? Also, could this cause any trouble later on, specifically with adding more than 8 devices to the network, say, if a friend brings a laptop round and wants to connect via wifi?

Also, is this really worth the fuss, or should I just NAT one IP address around?

Feel free to ask any questions if you need me to clarify anything.

Thanks.
July 15, 2006 8:18:29 PM

Does the router have a built in 4 port switch? if so then
I would configure it like this. cable modem -> switch ->router ->addon pcs.
Assign one ip to the router and the other 7 to the other computers.
If someone comes over and wants to hook up they will hook up thru the router which will be using dhcp.
Will speeds be any better this way? Probably not. The only problem is this will open up the computers connected to the switch to be open to attacks.

Hooking it up like you suggested: router -> switch -> pcs. You will need to turn off dhcp on the router which will make it act like a switch, which you dont really need. It would also make it difficult to add someone else to the network with internet access if all ips are taken.

I would just use the dhcp on the router. Dont know if they charge you extra for the other ip addresses or not. Most places do. Save some money and just nat the one ip address.
July 15, 2006 8:33:36 PM

Quote:
Does the router have a built in 4 port switch?
I haven't actually bought a router yet (I wanted to see how this discussion went before I made a choice), but every one that I've looked at had a 4-port switch included.
Quote:
cable modem -> switch ->router ->addon pcs.
Presumably the PC's would plug into the switch with this setup? That might be a good idea, I'll look into it.
Quote:
Dont know if they charge you extra for the other ip addresses or not. Most places do.
They don't, you just need to fill out a RIPE justification form if you want more than 5.

Thanks for the advice.
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July 16, 2006 4:30:39 PM

You did not say what bandwidth of the service is. If it is under 30 you may be in problem.

Most cable modems have a bandwidth of around 30mbps.

Some switches have port restrictions. which may help evenly distribute the service.
July 16, 2006 4:45:42 PM

Quote:
You did not say what bandwidth of the service is. If it is under 30 you may be in problem.
Cable is between 3 and 10Mbps (don't have the documentation to hand). DSL is 8Mbps.

Welcome to the UK :( 
July 16, 2006 4:50:27 PM

Hopefully the switch is a manage one, so you can evenly distribute the service. Bandwidth control will be needed.
July 18, 2006 1:22:31 PM

I wouldn't waste multiple IP addresses, in theory you can have about 65000 different connections with one IP address. We have companies that we do business for the get by with one IP address. If you want a lot of IPs then get them and if possible just create a NAT pool that way all your PCs get the security of NAT plus you have multiple IPs. But to me 5 people even if they are gamers won't have any trouble with one IP thats NAT'd plus most games aren't bandwidth intensive what so ever.
!