Can’t connect to mt PPTP VPN server

I was following this tutorial to configure a pptp connection between my centos 6 VPS and my fedora 22 workstation. There's only one thing I did different from that tutorial: I installed pptpd from the epel repository instead of the link provided.

I added the following rules to my iptables following the tutorial:

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE && iptables-save
iptables --table nat --append POSTROUTING --out-interface ppp0 -j MASQUERADE
iptables -I INPUT -s 10.0.0.0/8 -i ppp0 -j ACCEPT
iptables --append FORWARD --in-interface eth0 -j ACCEPT

I also added the following rule to make sure my farewall is not blocking my connection request:

iptables -A INPUT -s XXX.XXX.XXX.XXX -j ACCEPT

Where XXX.XXX.XXX.XXX is my workstation public fixed ipv4.

When i run:

pppd call pptpserver
ip route add 10.0.0.0/8 dev ppp0

I get RTNETLINK answers: Network is down for a few tries the I get Cannot find device "ppp0".

From journalctl -f I get:

pppd[7632]: pppd 2.4.5 started by user, uid 0
pppd[7632]: Using interface ppp0
pppd[7632]: Connect: ppp0 <--> /dev/pts/5
NetworkManager[1186]: <info> (ppp0): new Generic device (driver: 'unknown' ifindex: 15)
NetworkManager[1186]: <info> (ppp0): exported as /org/freedesktop/NetworkManager/Devices/14
pptp[7633]: anon log[main:pptp.c:333]: The synchronous pptp option is NOT activated
NetworkManager[1186]: <info> (ppp0): No existing connection detected.
pptp[7640]: anon log[ctrlp_rep:pptp_ctrl.c:258]: Sent control packet type is 1 'Start-Control-Connecti...equest'
pptp[7640]: anon log[ctrlp_disp:pptp_ctrl.c:758]: Received Start Control Connection Reply
pptp[7640]: anon log[ctrlp_disp:pptp_ctrl.c:792]: Client connection established.
pptp[7640]: anon log[ctrlp_rep:pptp_ctrl.c:258]: Sent control packet type is 7 'Outgoing-Call-Request'
pptp[7640]: anon log[ctrlp_disp:pptp_ctrl.c:877]: Received Outgoing Call Reply.
pptp[7640]: anon log[ctrlp_disp:pptp_ctrl.c:916]: Outgoing call established (call ID 0, peer's call ID 256).

A few secounds later:

pppd[7632]: LCP: timeout sending Config-Requests
pppd[7632]: Connection terminated.
avahi-daemon[874]: Withdrawing workstation service for ppp0.
gnome-session[2254]: Gjs-Message: JS LOG: Removing a network device that was not added
pppd[7632]: Modem hangup
pptp[7633]: anon warn[decaps_hdlc:pptp_gre.c:220]: short read (-1): Input/output error
pptp[7633]: anon warn[decaps_hdlc:pptp_gre.c:232]: pppd may have shutdown, see pppd log
pppd[7632]: Exit.
pptp[7640]: anon log[callmgr_main:pptp_callmgr.c:245]: Closing connection (unhandled)
pptp[7640]: anon log[ctrlp_rep:pptp_ctrl.c:258]: Sent control packet type is 12 'Call-Clear-Request'
pptp[7640]: anon log[call_callback:pptp_callmgr.c:84]: Closing connection (call state)

Does anybody has any clue what is wrong with my connection? Is it in my workstation or on the server?

Thanks