SSTP VPN behind NAT possible?

RouterOS General
1

Hi there,
i would ask if there is any possibility to get a vpn server based on sstp running behind a nat.
As you can see in the picture below, the lte router on the server side forwards every package to the mikrotik behind it.
But i was not able to establish the sstp tunnel. Ive already made some a vpn configuration with sstp but with directly internet connection and that works smooth.
So i thought that the issue my depends on the NAT on Server-Side.

Would be nice if anybody can give a feedback about that if it should working, one last idea from my side is, that i currently use 443 for sstp and that is the same port for the webinterface from the lte-router, so maybe there are some troubles and it didn’t get forwarded.


thx!
router.jpg

2

Not sure what you are trying to do but I have a similar situation and eevrything works great for me. I did start off trying EOIP over a PTPP tunnel but after these answers I went with SSTP clients calling back to a main router over a 4G connection which has cgnat.

See http://forum.mikrotik.com/t/eoip-over-pptp-vpn/134530/1

3

I simply want to create a sstp server behind an lte-router and establish a connection from the internet to this sstp server.

4

If this is true, then it should work. You can add rule like this:

/ip firewall mangle
add action=log chain=prerouting connection-state=new in-interface=<interface_connected_to_LTE_router> log-prefix=new_connection

and then try to connect to SSTP or any other port from internet and see if anything reaches RB.

5

What WAN IP address does your LTE Router have? If it’s a private address (which I think it will have unless you’ve paid extra) then the 4G carrier is using cgnat and won’t be forwarding inbound connections in.

If this is the case then going out through the LTE router (SSTP client to SSTP server) will work as established outbound connections are ok with cgnat.