Michael wrote:

quoted text
> Hello,

>

> I've got two "networks" connected with OpenVPN right now, the setup is

> like this.

>

> {Network_A}-----{OpenVPN_Server}------{Network_B}

>

> NetworkA is a real network where the router (with dynamic IP) is

> connected directly to a dedicated OpenVPN server with a static IP.

>

> "NetworkB" is just a single host within another network which is

> connected to the OpenVPN server to be able to directly access NetworkA

> over the central OpenVPN server.

>

> Now, as I understand it, it isn't possible to create an IPsec connection

> from a single host within a NATed network to an external server but

> OpenVPN works great here. Please correct me if I am wrong. (I have no

> access to the NAT router here.)

>

>

[snip]

Hi,
 From MY experience it is possible to use an IPSEC VPN through NAT, with

some conditions!!
1.  There can only be 1 IPSEC connection through the NAT router UNLESS

the router supports NAT-T.
2.  The IPSEC connection cannot be doing AH, only ESP.  If you do not

understand this statement, man(4) ipsec will be our friend.
Someone else may correct me, but these are my empirical findings and my

understanding from doing LOTS of reading.  I'm very much a beginner at

this stuff though.
The rest I have no idea about. 
Good Luck,

Steve Williams