Question: I've got two systems that are right next to each other, and connected wirelessly to the same router. I want to connect the two of them together with an ethernet cable - both have gig-e and autonegotiation so it should work. I DON'T need the second system to have internet, but I need any specific tweaks to be on that system only.

I do not need to *share* internet. I need RDP to work, and thats it

The wireless runs on a 192.168.1.x subnet and ICS always runs on a 192.168.0.x subnet so that wouldn't be a problem.

Ideally I want this layout. Can I do this with ICS, or there some other free or open source way? 

```
     +---------------------------+           +-----------------------------+
     | Laptop 1                  |           | Laptop 2                    |
     | Client- mobile            |           | 'server'- stationary system |
     |                           <-----+----->                             |
     | RDP client                |           | RDP Server                  |
     | MUST have wireless access |  ethernet | Runs ICS or similar         |
     +---------+-----------------+           | wireless access optional    |
               |                             +-----------------------------+
               |
               |
               |
               |
               |
               |
               |
               +---------------+     wireless to internet

```

Answer: 
Apparently, assuming one of your systems supports autonegotiation the following process will work

1. connect both the systems with an ethernet cable - a plain vanilla one will work with autonegotiation, else you'll need a crossover. Most modern systems support it.
2. You'll need to set up both systems with static IP addresses, ideally from one of the [3 private blocks](http://en.wikipedia.org/wiki/Private_network). Since most home networking uses the class C block, i chose to use the class A block, using the subnet mask 255.0.0 from [here](http://www.subnet-calculator.com/subnet.php?net_class=A).

Currently i don't know what is the proper default gateway to use for the 'server', so as far as the systems are concerned, its a private network - so any sharing will need the ports explicitly opened in the firewall. I need to work out how to fix this.

In order to set up static IP addresses 

go to Control Panel\Network and Internet\Network and Sharing Center

select change adaptor settings

![enter image description here](https://i.stack.imgur.com/2dJMS.png)

select the Local Area Connection/ethernet connection (it seems to vary between windows 7 and 8)

select properties 

![enter image description here](https://i.stack.imgur.com/mCtG0.png)

Select Internet Protocol Version 4 and hit properties

![enter image description here](https://i.stack.imgur.com/G4DqO.png)

I use these settings for the 'server'

![enter image description here](https://i.stack.imgur.com/p8mDw.png)

for the 'client'

![enter image description here](https://i.stack.imgur.com/V3IsV.png)

You can set the connection type as anything on the 'client' - it will be stuck as 'public' on the server.

3. you can test this with [ping](http://answers.microsoft.com/en-us/windows/forum/windows_7-networking/how-to-enable-ping-response-in-windows-7/5aff5f8d-f138-4c9a-8646-5b3a99f1cae6)
I have these settings on the two computers connected with a single RJ45 cable, and it worked:

```
PC-1 (windows 8)：
    IP: 192.168.200.1
    Mask: 255.255.255.0
    Gateway: 192.168.200.1
    DNS Server: <leave blank>

PC-2 (windows 7)：
    IP: 192.168.200.2
    Mask: 255.255.255.0
    Gateway: 192.168.200.1
    DNS Server: <leave blank>

```

I had to set the gateway, otherwise it's not working.