PPTPD fail on CentOS 5.4 VM

最近在玩VMware, VMware View4 及 XenDesktop4的應用, 為了方便管理把CentOS 5.4 也裝在虛擬機上面跑作為主要對外PPPoE的連接, 當在試讓VMware View4在WAN上跑都一直不能成功, 看官方的討論大都建議利用VPN來連接, 所以想說在CentOS 5.4上裝個簡單的PPTPD VPN Server 來試試, 但是一直都發現不能連入....很奇怪....會是因為虛擬機跑的問題嗎 @_@

Mar 25 04:07:13 orz101 pptpd[5292]: CTRL: Starting call (launching pppd, opening GRE)
Mar 25 04:07:13 orz101 pptpd[5292]: CTRL: Request to close control connection when call is open, closing
Mar 25 04:07:13 orz101 pppd[5612]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so is for pppd version 2.4.3, this is 2.4.4
Mar 25 04:07:13 orz101 pptpd[5292]: CTRL: Client 114.46.108.102 control connection finished
Mar 25 04:07:33 orz101 pptpd[5619]: CTRL: Client 114.46.108.102 control connection started
Mar 25 04:07:34 orz101 pptpd[5619]: CTRL: Starting call (launching pppd, opening GRE)
Mar 25 04:07:34 orz101 pppd[5620]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so is for pppd version 2.4.3, this is 2.4.4
Mar 25 04:07:34 orz101 pptpd[5619]: GRE: read(fd=6,buffer=610860,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs
Mar 25 04:07:34 orz101 pptpd[5619]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7)
Mar 25 04:07:34 orz101 pptpd[5619]: CTRL: Client 114.46.108.102 control connection finished