操作係統：ubuntu 14.04
我是是按照 http://blog.atime.me/note/l2tp_ipsec_installation_on_ubuntu.html 來配置的ipsec verify 出現錯誤，google了好久也沒找到解決方法。
> root@l:~# ipsec verify Checking if IPsec got installed and started
> correctly:
>
> Version check and ipsec on-path [OK] Openswan
> U2.6.42/K3.16.0-23-generic (netkey) See `ipsec --copyright' for
> copyright information. Checking for IPsec support in kernel
> [OK] NETKEY: Testing XFRM related proc values
> ICMP default/send_redirects [OK]
> ICMP default/accept_redirects [OK]
> XFRM larval drop [OK] Hardware random device check [N/A] Checking
> rp_filter [ENABLED]
> /proc/sys/net/ipv4/conf/all/rp_filter [ENABLED]
> /proc/sys/net/ipv4/conf/default/rp_filter [ENABLED]
> /proc/sys/net/ipv4/conf/eth0/rp_filter [ENABLED]
> /proc/sys/net/ipv4/conf/lo/rp_filter [ENABLED]
> Checking that pluto is running [OK] Pluto
> listening for IKE on udp 500 [OK] Pluto listening
> for IKE on tcp 500 [NOT IMPLEMENTED] Pluto
> listening for IKE/NAT-T on udp 4500 [OK] Pluto listening
> for IKE/NAT-T on tcp 4500 [NOT IMPLEMENTED] Pluto
> listening for IKE on tcp 10000 (cisco) [NOT IMPLEMENTED]
> Checking NAT and MASQUERADEing [TEST
> INCOMPLETE] Checking 'ip' command
> [OK] Checking 'iptables' command [OK]
>
> ipsec verify: encountered errors
另外，vpn是可以連上的，也可以訪問網絡，但是過一會就會出現錯誤，然後就無法訪問網絡了
> Nov 7 01:57:17 l pppd[14130]: script /etc/ppp/ip-down, pid 14156
> Nov 7 01:57:17 l pppd[14130]: Terminating on signal 15 Nov 7
> 01:57:17 l pppd[14130]: sending SIGTERM to process 14156 Nov 7
> 01:57:17 l pppd[14130]: Exit. Nov 7 01:57:17 l xl2tpd[13898]:
> get_call: can't find call 48693 in tunnel 40624#012 (ref=0/0) Nov 7
> 01:57:21 l xl2tpd[13898]: message repeated 81 times: [ get_call: can't
> find call 48693 in tunnel 40624#012 (ref=0 /0)]
希望大家可以幫助我解決這個問題
前面報錯的資訊太含糊了，誰也不知道錯誤和什麼相關，難道你執行的指令沒有詳細模式（verbose）嗎？