L2TP Server connection problem

I have setup the PPTP server on a Balance One as suggested here, however when attempting to connect from Windows 10, the dialog will stay in the “Connecting” status, but no connection occurs.

I suspect that the Balance is unreachable as we have 3 WANs and each WAN is returning a NATted IP judging from the IP itself clearly it looks like private IPs.

Should I disable NAT on the modems (at least one) to have the public IP assigned to the Peplink?

What risks are (for the modem) to have NAT disabled?


Any hint here?


You should have public IP on one of the Balance One’s WANs. I don’t see any risk after modem was configured as Bridge mode.

Hope this help.

I have a public IP, however I can’t connect and I get an error “The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with remote computer”.

Is it required some special configuration on the public IP? Open Ports?


Thanks to the tech support I got it to work!

The problem is that you cannot use some special characters in the preshared key as these aren’t saved correctly by the Balance One as of FW 6.3.1 b2256. Maybe this can be fixed in future updates of the firmware. I can use some special characters but not any from the complete set.

Problem solved! Thanks Peplink Team