PPTP 在Centos 7.1 建立方法与失效处理

# yum install pptp pptp-setup

pptpsetup --create vpn --server  (serverName) --username (Username)  --password  (Ps) --start

但是执行的时候没有正确的返回：

查了message log:

Jan  1 21:43:03 localhost pppd[25235]: Connect: ppp0 <--> /dev/pts/1

Jan  1 21:43:03 localhost pptp[25236]: anon log[main:pptp.c:333]: The synchronous pptp option is NOT activated
Jan  1 21:43:03 localhost pptp[25244]: anon
log[ctrlp_rep:pptp_ctrl.c:254]: Sent control packet type is 1
'Start-Control-Connection-Request'
Jan  1 21:43:03 localhost pptp[25244]: anon log[ctrlp_disp:pptp_ctrl.c:754]: Received Start Control Connection Reply
Jan  1 21:43:03 localhost pptp[25244]: anon log[ctrlp_disp:pptp_ctrl.c:788]: Client connection established.
Jan  1 21:43:04 localhost pptp[25244]: anon
log[ctrlp_rep:pptp_ctrl.c:254]: Sent control packet type is 7
'Outgoing-Call-Request'
Jan  1 21:43:04 localhost pptp[25244]: anon log[ctrlp_disp:pptp_ctrl.c:873]: Received Outgoing Call Reply.
Jan  1 21:43:04 localhost pptp[25244]: anon
log[ctrlp_disp:pptp_ctrl.c:912]: Outgoing call established (call ID 0,
peer's call ID 26624).
Jan  1 21:43:04 localhost pptp[25244]: anon log[pptp_read_some:pptp_ctrl.c:559]: read returned zero, peer has closed
Jan  1 21:43:04 localhost pptp[25244]: anon log[callmgr_main:pptp_callmgr.c:266]: Closing connection (shutdown)
Jan  1 21:43:04 localhost pptp[25244]: anon log[ctrlp_rep:pptp_ctrl.c:254]: Sent control packet type is 12 'Call-Clear-Request'
Jan  1 21:43:04 localhost pptp[25244]: anon log[pptp_read_some:pptp_ctrl.c:559]: read returned zero, peer has closed
Jan  1 21:43:04 localhost pptp[25244]: anon log[call_callback:pptp_callmgr.c:81]: Closing connection (call state)

Jan  1 21:43:04 localhost pppd[25235]: Modem hangup

解决方法：

modprobe nf_conntrack_pptp