VPN between two LANs (with ADSL routers)

[murph]

Hi,
i should make a VPN connection between two LANs. They are connected to
the Net through ADSL routers ( 4 ports ). I have a Win 2003 server in
LAN1 with two network adapters and have configured a basic VPN service
with MS2-CHAP authentication. When i try to make a VPN connection
from host in LAN1 to the server (it is also in LAN1) it works. The
problem is when i try to make a connection from LAN2, although i have
configured the ADSL router to route all the traffic for L2TP, IPSec,
PPTP to the server i receive error 800.
What can i eventually change ?

Q: Which of the two network adapters will win2003 default choose? How
can be that configured?

tx

 

[Robert L [MS-MVP]]

quoted from http://www.ChicagoTech.net
Error 800: Unable to establish the VPN connection. The VPN server may be
un-reachable, or security parameters may not be configured properly for this
connection.

Resolutions:
1) if you have firewall, open TCP Port 1723, IP Protocol 47 (GRE).
2) make sure you can reach the VPN server by using ping. Sometimes, poor
connection can cause this issue too.
3) You may need to updated firmware on a router or firewall if other OS
(win9x/nt/me/w2k) works except XP.
4) The VPN server may not be able to get IP from DHCP for the VPN client.
So, you may want to re-configure VPN host networking settings. For XP pro
VPN host, go to the Properties of the VPN>Network, check Specify TCP/IP
address and Allow calling computer to specify its own IP address, and
uncheck Assign TCP/IP addresses automatically using DHCP.
5) Make sure other secure software blocks your access, for example, if you
use Norton secure software, you may need to add the remote client's IP so
that the client can access.


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Robert Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN, Anti-Virus, Tips & Troubleshooting on
http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.

 

[Bill Grant]

800 is a very general message which just means the connection failed.
Change the client to try either PPTP or L2tp (rather than automatic) to get
a more useful message.

Can you ping the server? That's the first thing to check. If that works,
one or both of the routers is probably blocking a protocol or port which is
required. For PPTP you need TCP port 1723 .You also need IP protocol 47
(GRE) allowed in both directions on both routers.