能连接上VPN，但是上不了网，不知道什么原因

[weihua831]

日志文件：
Jun 17 03:10:38 guest pptpd[3932]: CTRL: Client 124.127.199.166 control connection started
Jun 17 03:10:39 guest pptpd[3932]: CTRL: Starting call (launching pppd, opening GRE)
Jun 17 03:10:39 guest pppd[3933]: Plugin /usr/lib64/pptpd/pptpd-logwtmp.so loaded.
Jun 17 03:10:39 guest pppd[3933]: pptpd-logwtmp: $Version$
Jun 17 03:10:39 guest pppd[3933]: pppd 2.4.5 started by root, uid 0
Jun 17 03:10:39 guest pppd[3933]: Using interface ppp0
Jun 17 03:10:39 guest pppd[3933]: Connect: ppp0 <--> /dev/pts/1
Jun 17 03:10:44 guest pppd[3933]: peer from calling number 124.127.199.166 authorized
Jun 17 03:10:46 guest pppd[3933]: MPPE 128-bit stateless compression enabled
Jun 17 03:10:48 guest pppd[3933]: Unsupported protocol 'IPv6 Control Protocol' (0x8057) received
Jun 17 03:10:48 guest pppd[3933]: Cannot determine ethernet address for proxy ARP
Jun 17 03:10:48 guest pppd[3933]: local IP address 172.16.36.1
Jun 17 03:10:48 guest pppd[3933]: remote IP address 172.16.36.2
Jun 17 03:10:48 guest pppd[3933]: pptpd-logwtmp.so ip-up ppp0 vpn 124.127.199.166
Jun 17 03:10:50 guest ntpd[1260]: Listen normally on 12 ppp0 172.16.36.1 UDP 123

[ghost]

没有开启转发