proxmox VM IP FO config

For each new VM
create virtual mac and add it to physical properties in network-device
under E100

then add this lines to /etc/network/interfaces

# 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 static
address #ip du FO#
netmask 255.255.255.255
broadcast #ip du FO#
post-up route add #ip passerelle#.254 dev eth0
post-up route add default gw #ip passerelle#.254
pre-down route del #ip passerelle#.254 dev eth0
pre-down route del default gw #ip passerelle#.254
dns-nameservers 213.186.33.99 8.8.8.8
dns-search ovh.net

and if the dns cant resolve add to /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.4.4

and 

service networking restart
ping google.com

(add also openssh server if not include by default)