Apple file sharing: bind to a specific interface

Sorry, I don't have much experience in setting up routers and such. You may want to post this question on another site, such as the site of the company that makes your router. You also can find the answer to this on searching on Google.

Are you using a particular file sharing service? If so, which one?

If I understand you, the two Macs are connected to the router (and thus to the internet) via Wifi, but for this copying you want to connect them directly using an ethernet cable. (I assume his Macs are reasonably recent and so don't require a crossover cable.)

In System Preferences>Network you will see a list of possible connections; where there is more than one the Mac concerned will choose the top one unless it isn't available, in which case it will drop to the next one.

You probably have wifi as the top one: if ethernet isn't there you need to add it and then drag it to the top of the list (on both Macs), then when you plug the lead in the Macs should be able to see each other using the normal File Sharing method and connect that way.

An alternative would be to create a new location, so that you have two locations, one wifi only and one ethernet only: then you could switch to the cable (turning the connection to the router off altogether). Again you would do this on both Macs.

This page has more details and may help:

http://www.applelinks.com/index.php/more/handson_mac_connecting_two_macs_via_a_simple_ethernetnetwork/

I can't help about any configuration of file sharing - I'm not sure there is one, I would expect it to use the current network connection, whatever that it. You could try the separate locations method - that ought to do it as, provided each has only the one connection method listed, it would turn Airport off when in Ethernet mode.

Is anything serving out addresses over the switch? If you set up the IP addresses of the Ethernet ports to different subnet from the wireless, you can use Connect to Server to connect to the other computer's IP address over Ethernet.

For instance, if your wifi is using 192.168.1.X, then set up Ethernet IPs on 192.168.2.X. Set the subnet mask to 255.255.255.0 and set the router to one of the computer's IP address. I haven't done this in a while, so just going on what I remember having to do.
You may need to configure one as the 'server' and just give it an IP address manually. Then, let the others connect to it over DHCP. If the other Macs get an IP address similar to the 'server' then you should be fine. If not, then give them all manual IP addresses to the first, just change the last octet.
Giving them all a manual address makes sure they are all the same when you want to connect to them because a self-assigned address will change.
Turn on File Sharing and use Connect to Server to connect to the computers via afp://192.168.2.X

Cesare Montresor wrote:
When i start the file sharing service it's bind automatically to the wifi interface only. That means that if you reach the other computer by the other ip it don't work because the daemon it's not listening on that address.

That means there is something wrong with your network configuration(s) on the Macs and/or your wired network configuration. As long as the Ethernet service is listed first in the Network System Preference on each Mac & the Network Diagnostics app (opened by clicking on the "Assist Me" button) shows the Ethernet network status indicators as all green, file sharing (& everything else) should use the Ethernet network connection.

Just as a diagnostic step, what happens if you temporarily turn off Wifi?

BTW, why do you need WiFi enabled on any of the Macs with Ethernet network connections anyway? As long as each of them can connect to the LAN over Ethernet they each should have full access to the other computers on the LAN & the wireless part of the network will perform better due to less radio traffic contending for the same limited bandwidth.

BTW, why do you need WiFi enabled on any of the Macs with Ethernet network connections anyway? As long as each of them can connect to the LAN over Ethernet they each should have full access to the other computers on the LAN & the wireless part of the network will perform better due to less radio traffic contending for the same limited bandwidth.

He said in his first post that the two computers were adjacent to each other but too far away from the router to be connectable by cable. He wants to copy from one to the other via cable to get the full ethernet speed on large files.

It's probably binding to the highest priority interface. Try changing the priority order so the wired ethernet comes first in the list before the wi-fi. Then reboot or restart the file sharing service.

Perhaps the switch is causing you problems. Have you tried just connecting the two straight together?

Roger Wilmut1 wrote:
He said in his first post that the two computers were adjacent to each other but too far away from the router to be connectable by cable. He wants to copy from one to the other via cable to get the full ethernet speed on large files.

I don't see anything in his posts that say it is just two computers or that they are adjacent, just that the switch is too far from the router to be connected to it by cable. I'm guessing that one of the Macs could have Internet sharing turned on, leave its WiFi on to do that, but that the others could get by without WiFi.