J'ai donc modifier les paramètres du serveur :
localip 192.168.1.160
remoteip 192.168.1.170-200
Les IPs sont bien dispo dans le /24 de la Livebox.
Petite amélioration :
Oct 31 15:48:44 vpn-wifioo pppd[23223]: pppd 2.4.6 started by root, uid 0
Oct 31 15:48:44 vpn-wifioo pppd[23223]: Using interface ppp0
Oct 31 15:48:44 vpn-wifioo pppd[23223]: Connect: ppp0 <--> /dev/pts/5
Oct 31 15:48:44 vpn-wifioo pppd[23223]: peer from calling number 78.223.xx.xxx authorized
Oct 31 15:48:44 vpn-wifioo pppd[23223]: MPPE 128-bit stateless compression enabled
Oct 31 15:48:44 vpn-wifioo pptpd[23222]: CTRL: Starting call (launching pppd, opening GRE)
Oct 31 15:48:44 vpn-wifioo pppd[23229]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
Oct 31 15:48:44 vpn-wifioo pppd[23229]: pppd 2.4.6 started by root, uid 0
Oct 31 15:48:44 vpn-wifioo pppd[23229]: Using interface ppp1
Oct 31 15:48:44 vpn-wifioo pppd[23229]: Connect: ppp1 <--> /dev/pts/6
Oct 31 15:48:44 vpn-wifioo pppd[23223]: found interface eth0 for proxy arp
Oct 31 15:48:44 vpn-wifioo pppd[23223]: local IP address 192.168.1.160
Oct 31 15:48:44 vpn-wifioo pppd[23223]: remote IP address 192.168.1.170
Oct 31 15:48:46 vpn-wifioo pptpd[23222]: CTRL: Reaping child PPP[23229]
Oct 31 15:48:46 vpn-wifioo pppd[23229]: Modem hangup
Oct 31 15:48:46 vpn-wifioo pppd[23229]: Connection terminated.
Oct 31 15:48:47 vpn-wifioo pppd[23229]: Exit.
Oct 31 15:48:47 vpn-wifioo pptpd[23222]: CTRL: Client 78.223.xx.xxx control connection finished
Oct 31 15:48:47 vpn-wifioo pppd[23223]: Modem hangup
Oct 31 15:48:47 vpn-wifioo pptpd[23221]: CTRL: Reaping child PPP[23223]
Oct 31 15:48:47 vpn-wifioo pppd[23223]: Connect time 0.1 minutes.
Oct 31 15:48:47 vpn-wifioo pppd[23223]: Sent 0 bytes, received 737 bytes.
Oct 31 15:48:47 vpn-wifioo pppd[23223]: MPPE disabled
Oct 31 15:48:47 vpn-wifioo pppd[23223]: Connection terminated.
Oct 31 15:48:47 vpn-wifioo pppd[23223]: Exit.
Oct 31 15:48:47 vpn-wifioo pptpd[23221]: CTRL: Client 78.223.xx.xxx control connection finished