Internet browsing

Hai,
I am using PPTP VPN since 2004 Dec.
I have absolutely no problem since then. From last two weeks, I have 
peculiar problem only for Windows users.
VPN connectivity is established without any problem, but users are 
unable to browse the internet. I am able to ping the VPN server and
name resolution is happening on the laptop. I am able to fully access 
all the servers and devices on the intranet. Any internet site, name 
resolution is
happening, but unable to get the webpage.
However, this problem is not seen for Linux VPN users.
Version of PPTPD installed is pptpd-1.3.4-2.el6.x86_64. Operating system 
is RHEL 6.2
Kernel details
Linux vpn 2.6.32-220.el6.x86_64 #1 SMP Wed Nov 9 08:03:13 EST 2011 
x86_64 x86_64 x86_64 GNU/Linux

No firewall is used on the VPN server. All these years, users with Linux 
and Windows were able to browse the internet after establishing VPN 
connection to server.

Is there any solution for this problem. Pl help me to resolve this problem.

Regards,
Raghavan.


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