I hope somebody can help me crack this nut.
Normally when the Mikrotik is gateway, I don’t have problems with the PPTP.
But my problem is now, that I’m behind another router, so when I’m connected to the Mikrotik PPTP I can ping 192.168.87.10, but I can’t ping the gateway router 192.168.87.1 and of course, don’t have Internet access through the PPTP tunnel.
My goal is of course to get access to the whole 192.168.87.0/24 network and get access to the Internet through the tunnel.
I have attached a drawing of the setup.
Anyone got an idea?
/Thomas
Really, no one had this challenge before?
For a scenario like this PPTP is the worst option you can choose.
Unfortunately, it’s not enough to forward tcp 1723 - you seem to have not thought about GRE (protocol 47)
Due to GRE’s nature, it’s not possible to forward this.
I’d rather suggest to use SSTP (tcp 443 only) or IPsec (UDP 500 and 4500).
Cheers
-Chris
Chris, I have to contradict this. It depends on the third party router…
If the MT router is the ONLY PPP server, then GRE (IP proto 47) can be forwarded by D-NAT to MT (The option is called something like PtP forward, or VPN forward or similar). If the router doesn’t feature this option, putting the MT in the router’s DMZ will also do it.
Right you are.
I guess it’s a bit too early for me to write sophisticated posts 
-Chris
Thanks for the answers.
I have no possibilities other than port forwarding in the 3. party router.
So do you suggest that I use a IPsec tunnel instead of using PPTP and find a VPN client for the computer?
Regards, Thomas
You will need port forwarding in that case, too.
But for SSTP it will be port 443 instead of 1723 + gre, which is easier to achieve.
On the other hand you will have to install some certificates…
Btw, Windows supports SSTP as client by default.