Web access slow after connecting to VPN

[GregB47304]

I am able to connect to the VPN just fine. The initial symptopms were that
the computer wanted to continue to use the local DNS (so it couldn't find
things like Exchange server and intranet) and loading external web pages was
slow. I was able to ping office servers by IP.

I corrected the DNS issue by editing the registry key
"HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Linkage\Bind",
putting "\Device\NdisWanIp" first. I can now connect to Exchange with Outlook
and ping office servers by name, but now the issue with the slow external
access remains. Simple pages like Google load, but, for example,
Microsoft.com and bing.com pages just sit there trying to load and never time
out (at least for as long as I have left it).

Anyone have any ideas? System is Windows XP Pro SP3 using Windows PPTP
client. I have verified with tracert that access to www.microsoft.com is
going over VPN and results of route print look good.

 

[John John - MVP]

That is normal because when you are connected by VPN you are most likely
accessing the internet via the host's gateway (the remote machine to
which you are connected) and upload speeds from most ISPs is usually
512kbps or less. In essence your internet requests/surfing are done by
the machine to which you are connected and then that machine uploads it
to your machine. Add the fact the host has to try to download and
upload at the same time and you get slow internet surfing while you are
connect to VPN. You can change your setup so that internet surfing is
done at your machine instead of the remote gateway but for security
reasons many network administrators do not like or want VPN users to do
this.

John

 

[Bob Lin \(MS-MVP\)]

Assuming this is Windows VPN, you may want to enable WINS for the name
resolution. Or assign server site's DNS. These search result may help.

How does RAS assign DNS/WINS to client
Name resolution is big issue in VPN access. If your VPN server doesn't
setup correctly ... To assign the DNS and WINS to a VPN client for name
resolution, . ...
www.howtonetworking.com/RemoteAccess/vpnname1.htm

Name resulotion on VPN
Jump to How to assign DNS and WINS on VPN client manually‎:
Click DNS and WINS tabs to assign the VPN server's DNS and WINS.
www.howtonetworking.com/nameresolutionpnvpn.htm



--
Bob Lin, Microsoft-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on
http://www.HowToNetworking.com

 

[GregB47304]

The VPN endpoint is a WatchGuard Firebox firewall. I worked with their
support and found a solution. On the PPTP VPN properties changed values for
MTU and MRU from 1300 to 1400 and web access works as expected now.

 

[Paul Brainard]

Hey can you give me a hint how to do this? I have the same problem, normal
internet access slows WAAAAAY down when I establish the VPN to a remote
server that is on a smaller (T-1) line than the 20 meg cable service I have
here. Then it goes back up to normal if I disconnect the VPN. Where can I set
the priority for sites/domains other than that one server?

Thanks!

 

[Enough to be dangerous]

Paul,

I had the same problem and it was driving me nuts! Here is the fix I found
on another board.

To fix the problem I opened the properties for the VPN connection on the
client -> Networking -> TCP/IP (Properties) -> Advanced -> and unchecked "Use
default gateway on remote network". After that both internet and my VPN
connection worked simultaneously.

 

[a2b]

Perfect reply, it works great, thank you very much

Paul,

I had the same problem and it was driving me nuts! Here is the fix I found
on another board.

To fix the problem I opened the properties for the VPN connection on the
client -> Networking -> TCP/IP (Properties) -> Advanced -> and unchecked "Use
default gateway on remote network". After that both internet and my VPN
connection worked simultaneously.


"Paul Brainard" wrote:

> Hey can you give me a hint how to do this? I have the same problem, normal
> internet access slows WAAAAAY down when I establish the VPN to a remote
> server that is on a smaller (T-1) line than the 20 meg cable service I have
> here. Then it goes back up to normal if I disconnect the VPN. Where can I set
> the priority for sites/domains other than that one server?
>
> Thanks!
>
> "John John - MVP" wrote:
>
> > That is normal because when you are connected by VPN you are most likely
> > accessing the internet via the host's gateway (the remote machine to
> > which you are connected) and upload speeds from most ISPs is usually
> > 512kbps or less. In essence your internet requests/surfing are done by
> > the machine to which you are connected and then that machine uploads it
> > to your machine. Add the fact the host has to try to download and
> > upload at the same time and you get slow internet surfing while you are
> > connect to VPN. You can change your setup so that internet surfing is
> > done at your machine instead of the remote gateway but for security
> > reasons many network administrators do not like or want VPN users to do
> > this.
> >
> > John
> >
> > GregB47304 wrote:
> > > I am able to connect to the VPN just fine. The initial symptopms were that
> > > the computer wanted to continue to use the local DNS (so it couldn't find
> > > things like Exchange server and intranet) and loading external web pages was
> > > slow. I was able to ping office servers by IP.
> > >
> > > I corrected the DNS issue by editing the registry key
> > > "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Linkage\Bind",
> > > putting "\Device\NdisWanIp" first. I can now connect to Exchange with Outlook
> > > and ping office servers by name, but now the issue with the slow external
> > > access remains. Simple pages like Google load, but, for example,
> > > Microsoft.com and bing.com pages just sit there trying to load and never time
> > > out (at least for as long as I have left it).
> > >
> > > Anyone have any ideas? System is Windows XP Pro SP3 using Windows PPTP
> > > client. I have verified with tracert that access to www.microsoft.com is
> > > going over VPN and results of route print look good.
> > .
> >