[vpn-help] VPN between shrew client and Zywall 2 plus

[Francis Meyvis]

Hello,

Following the guide at the support pages i succeeded setting up a
tunnel between
my ubuntu 10.04 client with shrew 2.1.5 and a Zywall 2 plus (latest firmware).
But there does not seem any traffic going back through the Zywall to
the shrew client.

With wireshark I see that clients behind the zywall receive the
incoming ping or sshd connection,
but the ssh client does not seem to receive the reply. The same is for a ping.
The machines behind the zywall firewall all have the zywall as their gateway.

Anybody knows what might be going wrong.
Anybody that could get past this issue?
Are there special firewall rules?
>From and to the VPN, all is permitted (I think these are default settings)

I played with the NAT option on the shrew client and at the Zywall but
that did not help.
I'm using the tap0 not the network interface itself as this does not
seem to work.

Thanks,
francis