Virtual Layer 3 Switch doesn't route on L2TP connection

[venerable]

Hi,
I'm a little bit confused, because I'm using SoftEther VPN Server with SoftEther VPN Client very well.
However I'm connecting with L2TP from my Android (4.0.4) or Windows7-Client I'm not able to reach the reverse side of the virtual L3 switch.

My setup:
I'm using SoftEther VPN Server x64 Ver. 4.08 Build 9449 on a Windows Server 2008 SP2.
I have configured two virtual hubs + a virtual L3 switch in the middle on one vpn-server.
On the L3 I attached two virtual interface in the defined network.
Additionally I have enabled SecureNAT on that virtual hub where I connect me from my clients. (However I think, I don't need this for that scenario. It's only for local bridge scenarios.)

How I described, if I connect with the SoftEther VPN Client anything is going very well for my.
However I'm using the standard L2TP VPN-Connection, I can only ping or reach the subnet with I connected.
I have changed the routing table on the device to using:
- only the tunnel (ppp0 or vpn-connection) 'ip route add 192.168.12.0/24 dev ppp0'
- to send 'everything' to the 'gateway' ip from the L3 switch 'ip route add 192.168.12.0/24 via 10.10.10.14'
- or to send 'everything' to the vpn-server (using maybe SecureNAT) 'ip route add 192.168.12.0/24 via 10.10.10.9'
,but nothing is going well.
The routes are accepted, if I look at the routing table they will be in.
When I try to make a tracert or pathping the first ip address shown is the ip from the vpn-connection.

So I don't know what I'm doing wrong.
Maybe anyone has an idea?

Regards,
venerable

http://www.adrive.com/public/mX98q4/SoftEthter.png

[venerable]

Hello again,
I have done some new tests with interesting insights.

I have tried to ping the L2TP machine from the other side
of the tunnel, where the machine is connected via SoftEther VPN Client.
And simultaneously I made a tcpdump at the L2TP machine to see,
if there any packets will be received.

And lo and behold, they are received.
However, the L2TP client/machine doesn't answer.
I only can see echo requests at the tcpdump but no echo reply.
So I think there is an issue with the vpn connection, because
I have verified my routing table so much,
that I don't belive there is anything wrong, I have even add a zero
route to the gatway ip (ip address from the virtual L3 switch).
Nothing!

How I told, there seems nothing wrong with the virtual L3 switch at
the SoftEther VPN Server. So I would say thank you to all
who have tried to solve my problem and close that case,
if there is nobody who can explain me why the vpn connection
doesn't route.

Regards,
venerable

[thisjun]

Actually L2TP client is behind an invisible router (ppp emulator) in VPN server.
Please use split tunneling function (Static routing table pushing function) instead of modifying routing table in L2TP client.

[Oooo1]

So, do SoftEther create ppp interface, but why is it not visible at OS as for example in case of xl2tpd/*swan ?

[thisjun]

Because SoftEther ppp emulator connected to the virtual hub instead of network stack of OS.