Softether and Router TP-Link blocking access

[dipling]

Dear all,

I bought a new router TP-Link TL-ER6120 to use load balancing because my old router lancom 1711
was to slow for a 200 MBit cable router.

After 3/4 day of Operation I can't connect to any Softether Server any more.
Looks like IP Adress is blocked when tryng to connect. But I can ping the destination DNS name.
Softether Log says:: The connection has been either disconnected or it failed. Cause: Connection to the server failed. Check network connection and make sure that address and port number of destination server are correct. (code 1)

If I switch back to the old router (using the same ISP) all connections are working.

Tried reset to factory default, stripped down Firewall of the router, removed load balancing,
nothing helped.

Is there any one that has an idea what operation of softether could cause a router firewall
with attack defense to block ? Any other VPN Client is working over that router (Cisco, Shrewsoft, Juniper / Netscreen, Sonic Wall).

Regards

Thomas

[thisjun]

Did you use VPN Azure or NAT-T?

[dipling]

I am using NAT-T.

The scenario is currently:

PC with Softether Client - TP-LINK Router - KABLE Router - Internet - NAT Router - Server with Softether Server.

If I replace TP-LINK Router with another router everything is OK.

THomas

[thisjun]

Please configure port forwarding on server side router.

[thisjun]

Some routers doesn't work with NAT-T.
Then, you need configure port forwarding manually.