Configuration errors will cause network exceptions, which will cause the machine to lose connection.

  1. Configure network

/etc/network/interfaces

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet manual

auto vmbr0
iface vmbr0 inet static
  address 1.2.3.4
  netmask 255.255.255.255
  gateway 1.2.3.254
  pointopoint 1.2.3.254
  hwaddress ether aa:bb:cc:dd:ee:ff
  bridge_ports eth0
  bridge_stp off
  bridge_fd 0
  bridge_maxwait 0
  1. Turn on forwarding

/etc/sysctl.conf

net.ipv4.ip_forward=1

Run sysctl -p refresh environment configuration

  1. Create nat network

/etc/network/interfaces

auto vmbr1
iface vmbr1 inet static
  address 10.1.1.254/24
  bridge-ports none
  bridge-stp off
  bridge-fd 0

Iptables

# OUT  
iptables -t nat -A POSTROUTING -s '10.1.1.0/24' -o vmbr0 -j MASQUERADE  

# IN  
iptables -t nat -A PREROUTING -i vmbr0 -p tcp --dport 10022 -j DNAT --to 10.1.1.100:22