I need to establish a PPTP connection from Linux based client to my Mikrotik PPTP server. (I know PPTP is bad etc...but I need to work with it for now).

upon connection the client log shows the error below. According to online docs http://pptpclient.sourceforge.net/howto ... mppe_bmanp this error means:

Diagnosis: you have given pppd the option require-mppe which forces the use of encryption, but the authentication phase did not use MS-CHAP[v2], it used something else. MPPE requires the use of MS-CHAP[v2] for establishing initial encryption keys. pppd terminates once it detects this conflict.

I have modified the default profile used by PPTP, and set Use Encryption to No, and Use Compression to No. But error does not change. Is there something else I need to change on the Mikrotik?

Mar 7 22:12:15 ip-172-31-25-10 pppd[18284]: Using interface ppp0
Mar 7 22:12:15 ip-172-31-25-10 pppd[18284]: Connect: ppp0 <--> /dev/pts/1
Mar 7 22:12:15 ip-172-31-25-10 pptp[18285]: anon log[main:pptp.c:333]: The synchronous pptp option is NOT activated
Mar 7 22:12:15 ip-172-31-25-10 pptp[18295]: anon log[ctrlp_rep:pptp_ctrl.c:254]: Sent control packet type is 1 'Start-Control-Connection-Request'
Mar 7 22:12:15 ip-172-31-25-10 pptp[18295]: anon log[ctrlp_disp:pptp_ctrl.c:754]: Received Start Control Connection Reply
Mar 7 22:12:15 ip-172-31-25-10 pptp[18295]: anon log[ctrlp_disp:pptp_ctrl.c:788]: Client connection established.
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[ctrlp_rep:pptp_ctrl.c:254]: Sent control packet type is 7 'Outgoing-Call-Request'
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[ctrlp_disp:pptp_ctrl.c:873]: Received Outgoing Call Reply.
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[ctrlp_disp:pptp_ctrl.c:912]: Outgoing call established (call ID 0, peer's call ID 371).
Mar 7 22:12:16 ip-172-31-25-10 pppd[18284]: MPPE required, but MS-CHAP[v2] nor EAP-TLS auth are performed.
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[pptp_read_some:pptp_ctrl.c:559]: read returned zero, peer has closed
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[callmgr_main:pptp_callmgr.c:266]: Closing connection (shutdown)
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[ctrlp_rep:pptp_ctrl.c:254]: Sent control packet type is 12 'Call-Clear-Request'
Mar 7 22:12:16 ip-172-31-25-10 pppd[18284]: Modem hangup
Mar 7 22:12:16 ip-172-31-25-10 pppd[18284]: Connection terminated.
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[pptp_read_some:pptp_ctrl.c:559]: read returned zero, peer has closed
Mar 7 22:12:16 ip-172-31-25-10 pptp[18295]: anon log[call_callback:pptp_callmgr.c:81]: Closing connection (call state)
Mar 7 22:12:16 ip-172-31-25-10 pppd[18284]: Exit.

That error indicates the client requires MPPE so setting the server profile use-encryption=no will certainly cause the connection to fail.

If you want an unencrypted connection configure the client not to ask for one. If you want an encrypted connection configure the PPTP server authentication=mschap2, the default-profile=default-encryption has use-encryption=yes