VPN causes Internet to stop

I have a desktop connected to a router via a cable and a laptop
connected to the same router via WiFi. Both work fine with static IPs.

I've set up a VPN between the laptop and the desktop with the latter
acting as a server.

The problem is that as soon as I open the VPN connection on the laptop
it's Internet connection stops working (and resumes immediately after I
disconnect the VPN).

This is my laptop ipconfig before VPN is connected.
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) PRO/Wireless 3945ABG
Network Connection
Physical Address. . . . . . . . . : 00-18-DE-B5-2A-F3
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.123.166
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.123.254
DNS Servers . . . . . . . . . . . : 212.150.49.10
192.168.123.254

And here it is with VPN connected:
Windows IP Configuration

Host Name . . . . . . . . . . . . : JACK-LAPTOP
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Wireless Network Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) PRO/Wireless
3945ABG Network Connection
Physical Address. . . . . . . . . : 00-18-DE-B5-2A-F3
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.123.166
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.123.254
DNS Servers . . . . . . . . . . . : 212.150.49.10
192.168.123.254

PPP adapter Home VPN:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
Physical Address. . . . . . . . . : 00-53-45-00-00-00
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.123.164
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 192.168.123.164
DNS Servers . . . . . . . . . . . : 212.150.49.10
192.168.123.254

Any ideas, guys?
Thanks


------------------------------------------------------------------------
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jackhab wrote:
> I have a desktop connected to a router via a cable and a laptop
> connected to the same router via WiFi. Both work fine with static IPs.
>
> I've set up a VPN between the laptop and the desktop with the latter
> acting as a server.
>
> The problem is that as soon as I open the VPN connection on the laptop
> it's Internet connection stops working (and resumes immediately after I
> disconnect the VPN).

Yes - thats normal. Once your laptop joins the VPN, it no longer has a
direct connection to the internet because it is inside the private network.

Solutions:
set up a proxy server to provide routing back out to the net.
RTFM for your VPN software, and see if there are any options.

jackhab <(E-Mail Removed)> hath wroth:

>I have a desktop connected to a router via a cable and a laptop
>connected to the same router via WiFi. Both work fine with static IPs.

Make, model, version?
Static IP on the WAN side of the router, LAN side, or both?

>I've set up a VPN between the laptop and the desktop with the latter
>acting as a server.

Laptop is at what IP address?
Desktop is at what IP address?
What program are you using for a VPN server on the laptop?
What program are you using for a VPN client on the desktop?

>The problem is that as soon as I open the VPN connection on the laptop
>it's Internet connection stops working (and resumes immediately after I
>disconnect the VPN).

Sure. That's normal.
If you happen to be using Microsoft PPTP VPN, then just change the
setting for the VPN default gateway to use the local default route,
instead of the remote default route.
Click on your PPTP connection icon
Don't connect.
Select Properties -> Networking -> Internet Protocol ->
Properties -> Advanced
Uncheck the box "Use Default Gateway on Remote Network".

However, since I only have a vague idea of what you have setup, my
guess(tm) is that it's alreay unchecked and the problem is that you
simply don't have an internet gateway (router) running on the VPN
server laptop.

You can find out for sure by running:
Start -> run -> cmd <enter>
route print

The results will be very different between when you have the VPN
running and when the VPN connection is disconnected (hangup). What
you'll probably see is that your default gateway is changing when you
run the VPN. If it points to an IP address that is *NOT* your router,
then you're not going have a connection to the internet.

Just what are you trying to accomplish with this arrangement and can
you be a bit less vague (i.e. some numbers please) with your
derrangement?

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

If you are using the Windows VPN dialer, open the properties of it, then the
TCP/IP properties, then advanced.
Uncheck the box that says "Use default gateway on remote network" and save.

Then try it.

"jackhab" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>
> I have a desktop connected to a router via a cable and a laptop
> connected to the same router via WiFi. Both work fine with static IPs.
>
> I've set up a VPN between the laptop and the desktop with the latter
> acting as a server.
>
> The problem is that as soon as I open the VPN connection on the laptop
> it's Internet connection stops working (and resumes immediately after I
> disconnect the VPN).
>
> This is my laptop ipconfig before VPN is connected.
> Connection-specific DNS Suffix . :
> Description . . . . . . . . . . . : Intel(R) PRO/Wireless 3945ABG
> Network Connection
> Physical Address. . . . . . . . . : 00-18-DE-B5-2A-F3
> Dhcp Enabled. . . . . . . . . . . : No
> IP Address. . . . . . . . . . . . : 192.168.123.166
> Subnet Mask . . . . . . . . . . . : 255.255.255.0
> Default Gateway . . . . . . . . . : 192.168.123.254
> DNS Servers . . . . . . . . . . . : 212.150.49.10
> 192.168.123.254
>
> And here it is with VPN connected:
> Windows IP Configuration
>
> Host Name . . . . . . . . . . . . : JACK-LAPTOP
> Primary Dns Suffix . . . . . . . :
> Node Type . . . . . . . . . . . . : Hybrid
> IP Routing Enabled. . . . . . . . : No
> WINS Proxy Enabled. . . . . . . . : No
>
> Ethernet adapter Wireless Network Connection:
>
> Connection-specific DNS Suffix . :
> Description . . . . . . . . . . . : Intel(R) PRO/Wireless
> 3945ABG Network Connection
> Physical Address. . . . . . . . . : 00-18-DE-B5-2A-F3
> Dhcp Enabled. . . . . . . . . . . : No
> IP Address. . . . . . . . . . . . : 192.168.123.166
> Subnet Mask . . . . . . . . . . . : 255.255.255.0
> Default Gateway . . . . . . . . . : 192.168.123.254
> DNS Servers . . . . . . . . . . . : 212.150.49.10
> 192.168.123.254
>
> PPP adapter Home VPN:
>
> Connection-specific DNS Suffix . :
> Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
> Physical Address. . . . . . . . . : 00-53-45-00-00-00
> Dhcp Enabled. . . . . . . . . . . : No
> IP Address. . . . . . . . . . . . : 192.168.123.164
> Subnet Mask . . . . . . . . . . . : 255.255.255.255
> Default Gateway . . . . . . . . . : 192.168.123.164
> DNS Servers . . . . . . . . . . . : 212.150.49.10
> 192.168.123.254
>
> Any ideas, guys?
> Thanks
>
>
> ------------------------------------------------------------------------
> View this thread: http://www.wirelessforums.org/showthread.php?t=33995
> http://www.wirelessforums.org
>

> If you are using the Windows VPN dialer, open the properties of it, then
the
> TCP/IP properties, then advanced.
> Uncheck the box that says "Use default gateway on remote network" and
save.

This is not necessarily a good idea. Let's say you WANT to tunnel ALL
traffic from the local machine through the VPN and THEN out to the internet.
I do this all the time if I'm using a laptop in an unsecured environment
(coffee shop, hotel, etc). ALL my traffic goes back to the office inside
the encrypted VPN, and then out from there to the Internet. If I were to
follow your advice I'd be screwed and leave all my internet traffic exposed
to being sniffed on the local unsecure network. Dumb idea.

What's necessary, however, is the receiving VPN to properly handle the
routing. Depends on which VPN server software is being used, and that's not
explained.

But one has to ask why are you trying to make a VPN connection inside the
same network?

-Bill Kearney

Bill Kearney wrote:
>
> But one has to ask why are you trying to make a VPN connection inside the
> same network?

I've seen it recommended as a lan security measure for wireless, ie the
same reason you do it in the coffee shop.

> > But one has to ask why are you trying to make a VPN connection inside
the
> > same network?
>
> I've seen it recommended as a lan security measure for wireless, ie the
> same reason you do it in the coffee shop.

But if it's your OWN network then just use one of the WiFi security
measures. And if it's not your own network, but one at the office, and
you're trying to hide traffic from management, well, that's not exactly a
good way to stay employed.

I'm not sure how well the routing tables on the laptop are going to tolerate
the situation. You're on network A, tunneling over to another device on
network A. Why shouldn't the routing just avoid the tunnel? So, you'd have
to create a different network 'inside' the tunnel. Say you're on
192.168.x.x locally, then make the tunnel 172.16.x.x. Then set the laptop's
default route to use the gateway on the receiving end of the tunnel (the
PC). Trouble is, you're still on the same network as the PC and it may well
short-cut that connection and avoid the tunnel.

-Bill Kearney

Bill Kearney wrote:
>>> But one has to ask why are you trying to make a VPN connection inside
> the
>>> same network?
>> I've seen it recommended as a lan security measure for wireless, ie the
>> same reason you do it in the coffee shop.
>
> But if it's your OWN network then just use one of the WiFi security
> measures.

I think the point is that WiFi encryption only encrypts the on-air
traffic. If your entire network is running as a VPN within itself, then
its encrypted throughout.

I didn't say by the way it was a _good_ idea... :-)