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I just checked that, even if I am home and connect to my work place through VPN, and check for my IP address, it is the same as my home's IP address.

(for example, using Google, and search for my ip, and Google will tell you your IP address).

So if I use my home computer, and check for the IP, and if I use my Macbook Pro which connected to my work's VPN (through my home wireless network), the IP are the same. I thought VPN works so that it is "as if I am at work", making it so that an intranet that I can't access at home become accessible because it is "as if I am at work", but then why and how can I show the IP as if I am at work?

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The VPN makes it so that it is "as if you are at work" when you access work machines. A VPN can also handle general Internet traffic, but it doesn't have to, and generally that just wastes resources and isn't done unless there's some specific reason to do so.

When you want to access Google, which makes more sense:

  1. You just send the packets to Google.
  2. Google just sends them back to you.


  1. You encapsulate the packets, encrypt them, and send them to your VPN endpoint.
  2. The VPN endpoint decrypts them and sends them to Google unencrypted.
  3. Google sends them back to the VPN endpoint.
  4. The VPN endpoint encrypted them and sends them back to you over the VPN.
  5. You receive them and have to decrypt them.

Notice how this makes all your traffic go over the VPN endpoint's Internet connection twice? And what benefit does this provide?

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so does that mean, if a URL, such as is found to be not accessible by my home network, then the browser (or the network drivers) will go the VPN route and try once again, and when that succeeded, use it (and maybe somehow even remember that this URL requires using VPN so next time it will use the VPN route directly) – 太極者無極而生 Dec 20 '12 at 17:37
No. It means the VPN is used to reach work machines and not used to reach other machines. The VPN modifies the system's routing table and operates at the IP level. – David Schwartz Dec 20 '12 at 17:43
so the VPN client has to be customized for what IP will go through the VPN, and if it is not one of those IP, then let it go through the regular home network. – 太極者無極而生 Dec 20 '12 at 17:45
The client is "customized" in this way by the VPN endpoint's server which pushes routes to it. In the server, you can typically onfigure the routes sent to the client. If you send a default route, then you get all traffic, including to sites like Google. – David Schwartz Dec 20 '12 at 17:48

Because you've made the assumption that all the traffic from your computer goes through the VPN.

VPN clients can be set up to shut off all routing to the local internet gateway and home LAN to route all the traffic from your computer through the VPN tunnel to the remote LAN which then makes the internet traffic come from the remote LAN's internet gateway router. You often are so limited you cannot even use a printer on your local home network if you've created one.

They also can be set up to do split routing where all the VPN routed traffic from your computer goes to the remote LAN it represents and all other traffic goes directly from your computer to your local home network and internet gateway.

VPNs are for protecting private traffic on a public network by establishing an encrypted tunnel, not for anonymity.

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That's because it defaults to split tunnel vs. full tunnel, which is better in many cases. You wouldn't want your torrents or random browsing habits to be monitored by IT, also that will increase latency, introduce bottlenecks, etc.

The difference here is basically where your default route is pointed in your routing table. If it's pointed at your work gateway, that's full tunnel, and if it's pointed at your "home" router gateway that's split tunnel.

If you want to send your traffic through your work for some reason, there are a couple things you can do.

  1. Is there a full tunnel option when you log in? Use that.

  2. Do you have a proxy server you have to use at work to get out? Set that up manually in your browser, now your http(s) traffic will come from your workplace.

  3. Change your default route to go through your VPN interface. Pull up your terminal and become root. route change default -interface $INTF where $INTF is probably like vpn0 or something. you can run ifconfig to check.

After you do this you may notice that you can't get to your printers, etc. do a route add -interface $INTF where $INTF is whatever you are using wlan0 or eth0.

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For Windows 8: Look if after connecting to the VPN your IP is still displayed as your home country (Google: What is my IP). If yes, open Windows Network center. Look if there is a new network adapter that has no internet connection. Click on it and as an admin, choose properties. Here, allow other users to use this connection und allow the connection for HTTPS and HTTP (or whatever you need to show the VPN IP). You may need to run the automatic Windows 8 troubleshooting wizard for the network and disconnect and reconnect the VPN service. Then, check if the new IP is displayed in your browser.

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