Two OSX Computers in Physical Proximity: Options?

I have two macs right next to each other. They are both on the same network and I can see both of them with a KVM switch and VNC (when the KVM is too annoying). However, I'd like a faster network connection between them, perhaps with low security. Is it possible to somehow use a cross-over cable to connect them, and then share things ONLY through that connection? Would that be faster, generally speaking, than my Wifi network (router is 5 years old at least)?

Dan Rosenstark

Posted 2010-10-11T15:28:05.563

Reputation: 5 718

2You don't need a special cable, the network cards can do the wire crossing on their own. Also, if you have Firewire on both sides, a host-to-host Firewire cable is a possibility (and might even be faster than Ethernet). – Gilles 'SO- stop being evil' – 2010-10-11T19:24:05.550

@Gilles holy cow, I had no idea... that explains why I can't find a cross-over cable at any of the local shops! I was just about to order it... regarding firewire, that's a great possibility too. I'll check that out right now (I hope that a host-to-host cable is not special in any sense). – Dan Rosenstark – 2010-10-12T15:14:27.870

@Gilles, firewire rocks, but is there any way to STOP the network sharing from happening on the Wifi connection? I only want to share via firewire. – Dan Rosenstark – 2010-10-12T15:24:02.823

2Every FireWire device is expected to be smart enough to control the connection, so there's no such thing as a specific "host-to-host" cable; all FireWire connections are host-to-host. – Ignacio Vazquez-Abrams – 2010-10-12T15:40:37.963

@Ignacio Vazquez-Abrams, thanks! I actually just hooked it up and tried it, worked with a Firewire 400 cable with no setup at all. But now I want to try Ethernet because I think it will be about 2+ times as fast. I only have Firewire 400 on one of the computers. – Dan Rosenstark – 2010-10-12T15:57:57.893

Thanks all, I tried Ethernet and it's so fast that a drive mounted on the other computer via Firewire 800 is faster than a drive mounted inside my Macbook... amazing! – Dan Rosenstark – 2010-10-12T21:30:45.637

Answers

Yes. To have them share across that connection, make sure you drag the ethernet connection to the top slot in the service order. Go to system preferences --> network. Click the little settings gear at the bottom of the list and choose "Set Service Order". It will likely already be first but it can't hurt.

Robert S Ciaccio

Posted 2010-10-11T15:28:05.563

Reputation: 1 470

So you're saying that the sharing will only happen for the first connection in the service order? – Dan Rosenstark – 2010-10-12T17:02:46.610

correct... it chooses the connection to use based on the service order and what is available through that service. so if it's able to connect to the other mac with the first service, it uses it. if it tries to connect to the internet, it goes through the service order as well, until it finds the first connection that is valid, which would be the wifi. – Robert S Ciaccio – 2010-10-12T17:08:00.023

@calavera, thanks for that. I see that I've been unclear. What I'm worried about is exposing the services (VNC and AFP server)... I ONLY want to expose them to the ethernet connection, NOT to the wifi connection. – Dan Rosenstark – 2010-10-12T21:29:32.643

@Yar: ahh.... let me think about that a bit and get back with you. – Robert S Ciaccio – 2010-10-13T01:07:20.770

@Yar: I looked around in the network preferences and I don't see anything that would prohibit those services from sharing on specific connections. I don't know of any other way to do this natively... although there may be a command line tool that I don't know about. You may want to check into some OS X firewall programs (the one that I've played with is little snitch). I know in Windows 7 you can set domain specific firewall rules, like for private networks allow this set of services, public these, etc. There may be an OS X firewall that provides similar functionality. – Robert S Ciaccio – 2010-10-14T04:13:17.163

Thanks! Unfortunately the built-in firewall doesn't allow this type of restriction either, and I think that Little Snitch only blocks outgoing connections, but that may be wrong... thx again – Dan Rosenstark – 2010-10-14T06:16:57.497

I think you're right on little snitch, and the built-in definitely doesn't have that functionality unfortunately. Maybe you should start a separate question for this on Apple.StackExchange.com... How can I share services over a specific network connection only? – Robert S Ciaccio – 2010-10-14T14:59:13.493

The connection will be much faster, and as long as you use the address given to the wired connection (or set the wired connection as the gateway for the other wireless address) apps will naturally use it.

Ignacio Vazquez-Abrams

Posted 2010-10-11T15:28:05.563

Reputation: 100 516

But I would want apps to use the wifi connection to connect to the world. Do I need to do anything special to split these functions? – Dan Rosenstark – 2010-10-11T17:37:06.477

No. The default gateway would still be the wireless connection. Only apps connecting directly to the other machine would use the wired connection. – Ignacio Vazquez-Abrams – 2010-10-11T17:39:10.470

that's perfect. I've decided to go with Firewire, which works, but is there any way to STOP the network sharing from happening across Wifi? I only want sharing with the firewire connection. – Dan Rosenstark – 2010-10-12T15:24:52.993

That I don't know. Presumably yes, but I don't know where that would be specified. – Ignacio Vazquez-Abrams – 2010-10-12T15:39:31.977

@Yar: I said how to do that in my answer... – Robert S Ciaccio – 2010-10-12T16:31:58.627