How to direct connection local lan + WIFI internet?

Question

I am running 2 computers.

Each have a WIFI connection to the router (other location in the house) which provides internet.

I would like now to directly connect those 2 computers via their Gigabit Ethernet card to provide fast file transfers between each computer because WIFI is too slow. The router is located too far to connect cables to also so I must use direct connection.

Computer 1 has Windows 2008 R2 (not running DNS server) Computer 2 is using OSx Mavericks

I have already successfully made direct connections where I have given below info to computer 1: IP: 192.168.2.1 / SUB: 255.255.255.0 and the rest I left empty, computer 2: IP: 192.168.2.2 / SUB: 255.255.255.0 and the rest I left empty.

But... this is the issue here... sometimes the internet stops working on either of them because for some reason a computer started thinking the internet should come from LAN and as such ignoring the WIFI internet connection.

I would like to know how I correctly should set up the computers LAN settings so I don't get interruptions on my WIFI internet.

Answer 1

This is a common problem with multi-homed machines (IP addresses on multiple subnets). The simplest solution is to assign (unused) IP addresses from the Wi-Fi subnet to the wired connections, using the same default gateway and subnet mask.

Answer 2

If there is no gateway set up, I see no reason it would act so.

But if there is gateway, then put big number (like 8000) to Metric (it's under Advanced in Windows, dunno in OS X), so this gateway priority will be low, and it won't be used to route internet traffic unless there is no other gateway.

Answer 3

In many attempts simple configuration of static IPs on 2 PCs will fail for seemingly unknown reasons (if you try it on the same subnet as proposed above or on a different one). You get no ping, and not even valid mac address resolutions shows up on arp -a command.

What works best for me (After failing the strait forward static ip approach) is using windows ICS(Internet Connection Sharing). It's the easiest most stable solution, as long as one of the PCs is connected via WIFI or another Ethernet to the internet. All you have to do is select to share the WIFI connection on the PC that has it. The Lan on this pc will get a static IP assignment by windows. The other PC should be set to DHCP. Also, consider disconnecting the WIFI on the computer that is using the shared connection to limit possible routing issues. This may not be a permanent configuration, but it works great for occasional very high speed backups, and will work with direct Ethernet connection between the computers as well.

Answer 4

You didnt state your ip addressing for your wifi.

I think you should use disjoint addressing patterns on both interfaces...

Eg if your wifi provides 192.168.1.0/24, configure your LAN interfaces on 10.2.0.0/24...or vice versa...

Then as usual, leave the gateway blank for the LAN connections... This should work ok I suppose.