How to use a Windows PC to share multiple network connections?

Question

I have a Windows PC (Win 7). It has a couple different network connections, including one that connects to a VPN, and one that connects to the Internet. I want to share both of those connections with other Windows PCs.

In other words, on Computer A, I can use the internet (through Connection #1) and my VPN (through Connection #2). How can I do the same thing (access the internet & VPN) on other computers (by somehow going through Computer A)?

You'd think this wouldn't be hard to do.

I've heard of ICS (Internet Connection Sharing), but that only seems to be able to share 1 network connection.

Solution 1

It looks to me like this has been answered before on SuperUser. The answer that makes sense to me goes like this:

1. Disable internet connection sharing if you have enabled it before
2. Select both adapters that you want to share. (Your Internet connection and your VPN connection)
3. Right click on one of selected and chose from dropdown menu "Bridge Connections" (or similar)
4. Enable Internet Connection Sharing and select the bridge as the thing you want to share.

EXPLANATION:

Bridging is what switches do. This makes Windows act like a switch, passing traffic between the bridged connections. ICS makes Windows act like a router so you are routing packets to your virtual switch.

SOURCE:

Windows 7 share internet connection with multiple network interfaces

Solution 2

Share multiple network connections by bridging them

If you do not care about traffic from Network 2 reaching Network 3 and vice versa (shown below) you can try this solution.

Select the three network interfaces you want to connect, click with your right mouse button and select Bridge Connections.

You should see another adapter appear named Network Bridge. Right click this device and select Properties to configure it.

Select Internet Protocol Version 4 (or six depending on your preference). Double click that or select Properties.

Switch to tab Alternate Configuration and enter your data depending on your setup. The most important is that you enter the correct Default Gateway, because that is the "door" your network traffic needs to reach the internet. The IP address you need to enter there is most likely the same IP your router has. If you're unsure about your DNS Servers it (again) is most likely your routers IP address. You should not have to enter a IP address for yourself (or Subnet mask) but you can.

If you don't know your routers IP address or gateway etc. you can find that out by opening a command prompt (cmd) and entering ipconfig /all.

Click OK and test your setup.

Comments

[HackSlash]

Possible duplicate: superuser.com/questions/656998/…

[harrymc]

What do you mean by "connection", are those two physical network adapters or just VPN over one Ethernet adapter?

[Tacony]

The VPN "connection" is a "virtual ethernet adapter" (which uses whatever the internet connection is). Does that answer your question?

[Tacony]

I tried this before. The problem is that when I do step #4 (for the MAC Bridge Miniport"), there is no "Sharing" tab - like there would normally be. The problem might have to do with the fact that I am trying to share 2 connections (instead of sharing 1 connection with 2 local interfaces as is described in the "source" you are talking about).

[HackSlash]

Right click on one part of the bridge, like the adapter that you are sharing with. Go to the sharing tab of that adapter, click Allow, and select the bridge from the dropdown.

[Tacony]

None of the 3 "connections" have a Sharing tab. The MAC bridge doesn't. And after bridging the 2 "child" connections, they don't have the Sharing tab anymore either.

[HackSlash]

The other option is manually set up static routing and enable routing with netsh forwarding=enabled. You're better off using a router for routing and windows for running software. Windows isn't the best router.

[HackSlash]

You've explained the switching well but this doesn't explain how to route packets to different networks. The OP wants to route packets to a VPN and to the internet. These are two different routes that need special routing rules to decide which packets go out which interface.

[Tacony]

Can you explain? Maybe add a 2nd method to your answer?

[HackSlash]

home-network-help.com/ip-forwarding.html

[Tacony]

I haven't tested your latest idea yet, but I'll give you the 50 now, because if I don't do it now, the bounty will expire. I'll let you know after I'm done testing.

[W.M.]

In fact, this solution makes allows all parties to communicate with each other on same LAN subnet. One issue I have observed though, is that the speed of the internet connection drops (from an upload speed of 10MB without bridge to 1MB with bridge). Maybe the best thing to do is to use physical switches.