Debian-8 sous virtualbox pas de réseau

Bonsoir,
je viens d’installer un debian 8. Je n’ai pas de connexion réseau. Voici quelques infos.
Machine hôte: debian-8
virtualbox: version 5.1.8
l’accés par pont: br0

La config réseau de l’hôte:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet manual

auto br0
iface br0 inet static
        bridge_ports eth0
        bridge_stp off
        bridge_waitport 0
        bridge_fd 0
        address 192.168.1.51
        netmask 255.255.255.0
        gateway 192.168.1.1
        dns-nameservers 192.168.1.1

ifconfig -a coté hôte

br0       Link encap:Ethernet  HWaddr 00:1e:ec:7b:a8:bf  
          inet adr:192.168.1.51  Bcast:192.168.1.255  Masque:255.255.255.0
          adr inet6: fe80::21e:ecff:fe7b:a8bf/64 Scope:Lien
          adr inet6: 2a01:cb1c:8e0:9100:21e:ecff:fe7b:a8bf/64 Scope:Global
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:14179 errors:0 dropped:369 overruns:0 frame:0
          TX packets:11617 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 lg file transmission:0 
          RX bytes:9733596 (9.2 MiB)  TX bytes:1995448 (1.9 MiB)

eth0      Link encap:Ethernet  HWaddr 00:1e:ec:7b:a8:bf  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:16801 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11617 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 lg file transmission:1000 
          RX bytes:10167531 (9.6 MiB)  TX bytes:1995448 (1.9 MiB)

lo        Link encap:Boucle locale  
          inet adr:127.0.0.1  Masque:255.0.0.0
          adr inet6: ::1/128 Scope:Hôte
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:181 errors:0 dropped:0 overruns:0 frame:0
          TX packets:181 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 lg file transmission:0 
          RX bytes:13531 (13.2 KiB)  TX bytes:13531 (13.2 KiB)

wlan0     Link encap:Ethernet  HWaddr 00:16:ea:4b:48:74  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 lg file transmission:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

La config réseau coté machine virtuelle, ip en dur