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Hi,<br />
I'm trying to configure VPN client on Windows OSes (L2TP/IPsec with psk) but I got some obstacles.<br />
Environment is:<br />
<br />
WIN VPN CLIENT &lt;------&gt; NAT DSL ROUTER &lt;----------- INTERNET -----------------&gt; ISP FW ------------&gt; SERVER<br />
<br />
My goal is to reach server through IPsec tunnel.<br />
I opened udp ports 500, 1701 and 4500 on ISP FW (DNAT to Server's IP).<br />
I also modified registry on Windows (by creating this DWORD AssumeUDPEncapsulationCont<wbr />extOnSendR<wbr />ule with value = &quot;2&quot;, as Microsoft suggests).<br />
<br />
I do see traffic on ISP FW, but VPN connections fails.<br />
Is NAT-T truly possible on Windows OS with native VPN client?<br />
<br />
Thank you
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Hi,
I'm trying to configure VPN client on Windows OSes (L2TP/IPsec with psk) but I got some obstacles.
Environment is:

WIN VPN CLIENT <------> NAT DSL ROUTER <----------- INTERNET -----------------> ISP FW ------------> SERVER

My goal is to reach server through IPsec tunnel.
I opened udp ports 500, 1701 and 4500 on ISP FW (DNAT to Server's IP).
I also modified registry on Windows (by creating this DWORD AssumeUDPEncapsulationContextOnSendRule with value = "2", as Microsoft suggests).

I do see traffic on ISP FW, but VPN connections fails.
Is NAT-T truly possible on Windows OS with native VPN client?

Thank you

Windows, IPSec and NAT-T

Internet Protocol Security (IPsec) is a protocol suite for secure Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session. IPsec includes protocols for establishing mutual authentication between agents at the beginning of the session and negotiation of cryptographic keys to be used during the session. IPsec can be used in protecting data flows between a pair of hosts (host-to-host), between a pair of security gateways (network-to-network), or between a security gateway and a host (network-to-host). IPsec is an end-to-end security scheme operating in the Internet Layer of the Internet Protocol Suite.

Internet Protocol Security

A virtual private network (VPN) is a network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or travelling users access to a central organizational network securely. VPNs encapsulate data transfers using secure cryptographic methods and other security mechanisms to ensure that only authorized users can access the network and that the data cannot be intercepted.