How do I share the internet from my desktop to my laptop?

May 3, 2004 1:00 PM

I have a Hub, a desktop and a laptop. The desktop is currently hooked up to the net via Rogers. How do I arrange to have the internet access shared with the laptop? [more inside]

I know this is likely a simple thing to do, but I can't seem to manage it. A former roommate and I had this set-up (I didn't hook anything up though), but we had made it official and ordered a second IP address from Rogers. Is this really necessary?

I tried connecting it all, (cable modem to hub, each computer to hub) and nothing. I cannot seem to find any simple instructions. I feel stupid for not being able to do this, so thanks for helping.

posted by aclevername to computers & internet (17 comments total)

Just to clarify, I don't have the second IP address now, and hey, I'm cheap, if I don't need to order it - even better!
posted by aclevername at 1:05 PM on May 3, 2004

You don't mention what operating system, but let's assume windows for the heck of it. Google for internet connection sharing.
posted by fvw at 1:19 PM on May 3, 2004

You need a Router, not a Hub.
posted by falconred at 1:20 PM on May 3, 2004

Oops, I meant Hub.

You could do some sort of spooky connection sharing like fvw mentions, but you really should get a router because it has a NAT firewall to keep the nasty worms away.
posted by falconred at 1:22 PM on May 3, 2004

i can't think of any solution where you need two internet addresses unless you want to run servers of some kind.

if your computer runs linux, you can do this, but it's not trivial. best bet is to buy a router - might as well get a wireless one. see if you can sell the hub (unless the hub is, in fact, a router ;o)
posted by andrew cooke at 1:53 PM on May 3, 2004

falconred, connection sharing is usually done using NAT.

andrew cooke, it's very trivial under linux (as long as netfilter is compiled into the kernel (which for most distros these days is true)... and you have two NICs)... like a couple lines worth of changes trivial.

Incidentally, If you are running linux, google for "linux ip masquerading" or "linux iptables nat". Or just contact me. Or post here.
posted by thebabelfish at 1:57 PM on May 3, 2004

Wireless 802.11 routers, by the way, can be had for as little as $5 now.
posted by kindall at 2:00 PM on May 3, 2004

So there's no way to do this with a Hub? I've had it set up to do so before, but it may have been contingent on the second IP address. Unfortunately I am no longer in touch with the fellow who set it up the last time to ask him what the heck he did.

And I'm running Win XP.
posted by aclevername at 2:19 PM on May 3, 2004

"Internet Connection Sharing" will work just fine, there's plenty of help and walkthroughs for it on Microsoft's help system and WWW sites.
posted by Space Coyote at 2:36 PM on May 3, 2004

It can definitely be done with the hub. You'll need to make sure that you have two network adaptors in the desktop computer, and follow the instructions on this page from Microsoft.

They're right, though. You'd be better off getting a stand-alone router, preferable one with a nice built-in firewall. Less than $50; we've had discussions on which ones work best on AskMe previously.
posted by mr_roboto at 2:37 PM on May 3, 2004

That said, we need a name for these things other than "router". This is a router. What we're talking about in this thread is a multifunction network interface box for home users that acts as a NAT server, DHCP server, firewall, router for the translated network, wireless interface controller, etc. Has anyone heard of a better term for these boxes? I'm about to get one to replace my linux NAT/DHCP/firewall box/power sink/white noise generator, and I'd like to know what to call it.
posted by mr_roboto at 2:54 PM on May 3, 2004

In a sense, it is still a router, since it performs routing functions, but it just happens to have other functions as well.

Anyway, you're right, we need a better word. I propose 'wapigras' (WirelessAccessPointInternetGatewayRouterAndSwitch).
posted by chrismear at 3:22 PM on May 3, 2004

I've seen variations on "internet access gateway" or "broadband gateway". I think I like it, though there's some potential for confusion with generic IP gateway hosts (which they are an instance of).
posted by mote at 3:25 PM on May 3, 2004

Am I the only one who parsed (as long as netfilter is compiled into the kernel) as (as long as metafilter is compiled into the kernel)?
posted by theora55 at 5:52 PM on May 3, 2004

In any case, clever, you connect your broadband device to a router/gateway/Wireless Access Point. It takes your ISP-assigned IP address, and provides multiple IP addresses inside your home 1. You can usually connect via wireless or wired connection. Your laptop 2. may have a wireless adapter built in. If not, it's well worth having, and a laptop wireless adapter shouldn't be too expensive.

A hub can only provide connectivity in an environment where additional IP addresses are available. My broadband provider used to let us have 5 IP addresses, so a hub worked. They limit me to 2 IP addresses now, and most ISPs only give you 1 IP address. 3.

1. Wireless security is usually off by default. You may be providing access for passersby and neighbors.

2. Newer laptops are implementing builtin wireless.

3. If anybody does know how to compile metafilter into the kernel, I'd like to see that.
posted by theora55 at 6:09 PM on May 3, 2004

theora55 - as far as i can see, the solution described in mr_roboto's link works fine with a hub (it appears that win xp has nat built-in). so that is a solution with a hub and a single address.

however, it means connecting a windows machine directly to the net, which isn't that cool (with a personal firewall and "client for microsoft networks" disabled in network properties it might be ok).
posted by andrew cooke at 7:19 PM on May 3, 2004

(and it requires two network cards, of course)
posted by andrew cooke at 7:20 PM on May 3, 2004