ad-hoc networking blues

January 11, 2006 1:41 PM

How do I set up a laptop to do ad-hoc networking through the wired NIC?

A friend and I are trying to share large files (~ 3-5 GB) during the short times we have free simultaneously. Numerous free WiFi b-g networks exist in the area, but all of them block file sharing for relatively obvious security reasons.

Windows ad-hoc wireless is horrid, and would take hours for a few hundred megs, let alone multiple gigs. We want to circumvent this using ad-hoc on the normal wired ethernet NIC.

I used to know how on Win95, but not only have I forgotten but I'm not using that version anymore anyway. The laptops are using WinXP Pro and Win XP Tablet.

posted by mystyk to Computers & Internet (4 answers total)

First off, make sure you use a crossover cable when connecting them. If both nics are set to DHCP, then they will self-assign a non-routable IP address in the absence of a DHCP server. That's as close to ad-hoc as you can get. You can, of course, assign the NICs addresses manually, such as 10.0.0.1 and 10.0.0.2 to accomplish the same.
posted by pmbuko at 1:48 PM on January 11, 2006

Simplest: get an ethernet hub or something. It's not like they're expensive.

Otherwise for a direct connection you'll need an ethernet crossover cable - which is not the same as a regular ethernet cable. (This is probably your problem.) Set up both PCs with compatible network settings for their NICs, and you're off.
posted by jellicle at 1:51 PM on January 11, 2006

Before you go buy a crossover cable, you might want to try setting things up with a standard ethernet cable first. Some modern network cards can automatically detect/switch into crossover mode (I know that the new iBooks have this feature, for example) - So if at least one of the two ports can switch automatically, it might save you some time/money.
posted by helios at 3:08 PM on January 11, 2006

Easiest thing with Windows is to actually do Internet Connection Sharing. Either set it up on an existing WLAN, LAN or Serial port connection that isn't connected, or create a Serial Network driver out thin air.

(Control Panel -> Add New Hardware -> Yes, I have connected it. -> Add New Hardware Device -> Install the hardware that I manually select from a list -> Network Adapters -> Microsoft -> Microsoft Loopback Adapter -> Finish )

This will turn on the native ICS DHCP Server, and make it so that both systems are on a valid IP network/subnet combo. You'll also see each other pop up in Network Places as long as no firewalls are in the way.

This does get rid of your settings though- a pain in the ass.

The real good thing to do is to hit Network Connections, edit your LAN, select TCP/IP and click Properties. Hit the Alternate config tab, and put in an IP of 10.x.x.x and subnet of 255.0.0.0. Save these settings, and then let the computers sit for about 5 minutes. After they time out from being unable to get an IP, they will default to this IP.
As long as you put in x's that are different on each machine, it will work fine.

You will need a crossover or a hub!
posted by id at 3:23 PM on January 11, 2006