Question : Problem: LAN to LAN VPN  (LAN1 - Linux <------ Draytek 2600Vg -- LAN2) problem LAN2 ping LAN1, and VPN connection keeps dropping

Hello

I'm trying to connect 2 LANs from LAN2 to LAN1.
the problem is that in a computer in LAN2 I cant ping LAN

setup

192.168.10.x ------
                \
                  Linux - alcatel speedtouch i550 - WAN      Draytek 2600Vg <--- 10.0.0.x
                /
192.168.1.x  ------


in LAN1

linux is accepting all connections configured as a server in speedtouch
linux is acting as a firewall and acepting VPN connections
linux VPN protocol is PPTP and the daemon is configured with no compression (no ccp option)
There is a primary domain controler (PDC) that authenticates users in domain
PDC as also a DNS to resolve LAN names
everything is connected by a switch
linux has 2 ethernet controlers one for 192.168.10.x other for 192.168.1.x


in LAN2
Draytek acts as a firewall
acts as a modem for ADSL
makes the VPN connection to LAN1
the route table when the vpn is connected is


    Key: C - connected, S - static, R - RIP, * - default, ~ - private

    *             0.0.0.0/         0.0.0.0 via 82.154.96.1, IF3  (WAN)
    C~           10.0.0.0/   255.255.255.0 is directly connected, IF0
    C~      192.168.10.12/ 255.255.255.255 is directly connected, IF4
    S~       192.168.10.0/   255.255.255.0 via 192.168.10.12, IF4

192.168.10.12 is the ip of linux ppp interface
the ip given to the draytek router is in range 192.168.10.20 to 192.168.10.30

problem:
can't ping from inside LAN2 to LAN1
connection keeps dropping after around 4 minute (tops) even if I am pinging LAN1 from the router

Facts:
If I connect from a XP client directly connected to the internet
 to VPN in LAN1 I have no problem and I can resolve names in LAN1 and ping
In a telnet session in router I can ping LAN1


To me looks like a route that is missing, but can't understand the connection dropping

I have to figure this way out, or I can work another solution.
If you thing of a better solution to connected both LANs please give your
advise, I'll try to split points to the best sugested solutions.

thanks

Answer : Problem: LAN to LAN VPN  (LAN1 - Linux <------ Draytek 2600Vg -- LAN2) problem LAN2 ping LAN1, and VPN connection keeps dropping

From my point of view, you have no backroute configured for the network 10.0.0.x in LAN1

If you connect directly Draytek (when on telnet session) or a winXP client, you don't need a backroute, as it is directly connected (and the route is implicit made at the linux box) ... it gets an IP 192.168.10.20 to 192.168.10.30
But when you want to ping from 10.0.0.x via the interface of the 192.168.10.x of draytek, the LAN1 doesn't know, how to reach 10.0.0.x .. you must define it via the VPN interface at the linux box

Holger