I don't understand why! Here is the log
14:48:01 ipsec,info purging ISAKMP-SA 1xx.xx.xx.xx[4500]<=>1xx.xx.xx.xx[11659] spi=59bd8xxc0a02160c:2181ecxxxx57.
14:48:01 ipsec,info ISAKMP-SA deleted 10x.xx.xx.xx[4500]-1xx.xx.xx.xx[11659] spi:59bd8xxc0a02160c:2181ec3xxxxc57 r
ekey:1
15:34:03 ipsec,info ISAKMP-SA dying 10x.xx.xx.xx[500]-41.xx.xx.xxx[500] spi:26273c7cb26a2c4b:dxxxxx73c0253
15:46:03 ipsec,info ISAKMP-SA deleted 10x.xx.xx.xx[500]-41.xx.xx.xx[500] spi:26273c7cb26a2c4b:dxxxxx73c0253 rekey:1
15:46:28 l2tp,ppp,info <l2tp-skynet>: terminating... - hungup
15:46:28 l2tp,ppp,info,account skynet logged out, 3624 497254 xxxxxxxxx
15:46:28 l2tp,ppp,info <l2tp-skynet>: disconnected
16:49:57 ipsec,info respond new phase 1 (Identity Protection): 1xx.xx.xx.xx[500]<=>xx.xx.xxx.xx[500]
16:49:58 ipsec,info ISAKMP-SA established 1xx.xx.xx.xx[500]-4xx.xx.xx.xx[500] spi:eaxxxxxxx4:0aa11562e395c5fe
16:49:59 l2tp,info first L2TP UDP packet received from 4xx.xx.xx.xx
16:49:59 interface,info <l2tp-skynet> detect UNKNOWN
16:49:59 l2tp,ppp,info,account skynet logged in, 10.xx.xx.12
16:49:59 l2tp,ppp,info <l2tp-skynet>: authenticated
16:49:59 l2tp,ppp,info <l2tp-skynet>: connected
16:50:05 interface,info <l2tp-skynet> detect WAN