Internet goes down when connecting with VPN

[O2BNSV]

I am running vista ultimate. When I try to access a client's network via VPN, I lose access to the internet and thus, have no access to files on the network. Does anyone know how to resolve this?

 

[wcburton]

Your problem may be software - not hardware. You may have more luck posting in a different forum. What VPN client? MS or Cisco or other? What VPN server? More details lead to better answers.

 

[wahnula]

I had a problem with my SonicWall Global VPN Client completely choking my SMC router...if you have a router on your network try going around it (removing it temporarily). If you now have access then your router is either choking or not set up to allow VPN traffic.

I solved my problem by going with a D-Link VPN/Router which enables VPN ports by default. You may also need to configure Vista to allow the VPN port (1723 I believe) to be available.

Tony

"...an eye for an eye leaves everybody blind" - M.L. King

 

[kmcferrin]

It can vary from router to router, but another common issue with IPSec VPNs is that you usually need to enable NAT Traversal (NAT-T) if you are connecting from behind a NAT device (router). Also, if the IPSec VPN is working in Tunnel mode instead of Transport mode you can end up with larger frames/packets than are normally supported. This can lead to packet fragmentation, which will cause connection problems.

But all of that assumes that it's an IPSec VPN and not SSL or something.

One more thing to consider is that some VPN clients will block access to all traffic that doesn't go through the VPN tunnel to the remote end as a security mechanism. I have used IPSec clients from NetScreen and Fortinet that would do this.

 

[IRudebwoy]

Depending on the VPN client software all other connections to the LAN/WAN excluding the VPN connection may cease to function while connected to the VPN. A security feature of the software.

 

[Sympology]

Yup our Nortel VPN's do this....

Only the truly stupid believe they know everything.
Stu.. 2004

 

[O2BNSV]

Wow. There's a lot more going on than I could have figured out. I probably need to make sure my router is configured correctly. I am not using any special VPN client software. I've simply created a VPN connection using Vista's connection wizard. I don't know if that makes a difference, but I now know where to start. Thanks.

 

[kmcferrin]

I would suggest that you move it to the Windows Vista forum. One thing that I do know for sure though is that when you're setting up a VPN connection via the wizard Vista doesn't really let you configure any options until after the VPN is created.

What are you connecting to on the other end? Is it a Microsoft RRAS setup?

 

[wahnula]

I would recommend a hamachi VPN, very easy to set up & use..made for the 'rest of us'. Even folks that have never done this before don't worry...I'LL Post a guide if you're still having trouble. Keep he faith

Tony

"...an eye for an eye leaves everybody blind" - M.L. King

 

[kmcferrin]

While we're making recommendations, I can highly recommend using products that make use of SSL VPNs instead of IPSec VPNs. Most of the ones that I have seen allow you to initiate a tunnel by accessing a web site. Some require an ActiveX control to operate. But they require almost zero setup on the client side.

 

[O2BNSV]

I've really narrowed this down. It is not a vista issue. The VPN connection works from any network but my home wireless network. This tells me it's a router issue. If anyone has any tips on router configuration, I would appreciate it.

 

[acewarlock]

Before you spend more time trying to figure this out, connect your cable modem directly to your laptop to make sure you can connect and do what your trying to do. if you still can't do it, it's not a router problem.




This is a Signature and not part of the answer, it appears on every reply.

This is an Analogy so don't take it personally as some have.

Why change the engine if all you need is to change the spark plugs.

 

[O2BNSV]

I already have. Sorry forgot to mention that. This connection only fails when I am either wired from my wireless router or when I am connected wirelessly to my wireless network. It works everywhere else I have tried it.

 

[acewarlock]

OK I'm not going to be able to help on that one, but if you supply the make and model of your router someone else maybe able to help.




This is a Signature and not part of the answer, it appears on every reply.

This is an Analogy so don't take it personally as some have.

Why change the engine if all you need is to change the spark plugs.

 

[O2BNSV]

I think this is the correct place to continue this post now that the issue has been localized. If not please let me know where to repost. My wireless router is a Netgear WNR834Bv2. I called their support line and they helped me open all the ports that are supposedly necessary for a vpn tunnel to work. Any input would be greatly appreciated.

 

[wahnula]

Like I said in my first response, some routers simply cannot handle a VPN...like my SMC Barricade (2804 I think?). It completely locked up, all ports dead, and had to be rebooted to get it to work again briefly, until I tried to connect via VPN. The correct ports were open, it just choked on the connection.

I just happened to have a D-Link 804HV sitting around and it makes a wonderful VPN router, I use it with a WAP for wireless duties. If you can find a VPN router that works you can then connect the Netgear as a wireless access point (for non-VPN traffic), just set the VPN router to be DHCP server and shut the Netgear's DHCP off.

My recommendation...get a router locally that you can return if it does not work.

Tony

"...an eye for an eye leaves everybody blind" - M.L. King