Este documento toma elementos de la configuración mostrada en Using private IPs for Hardware Nodes.

iWeb entrega el sistema configurado así:

 # ip addr show
 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
     inet 127.0.0.1/8 scope host lo
     inet6 ::1/128 scope host 
        valid_lft forever preferred_lft forever
 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 10
     link/ether 00:1b:21:28:d5:15 brd ff:ff:ff:ff:ff:ff
     inet 70.38.78.182/27 brd 70.38.78.191 scope global eth0
     inet 70.38.83.81/29 brd 70.38.83.87 scope global eth0:1
     inet 70.38.83.82/29 brd 70.38.83.87 scope global eth0:2
     inet 70.38.83.83/29 brd 70.38.83.87 scope global eth0:3
     inet 70.38.83.84/29 brd 70.38.83.87 scope global eth0:4
     inet 70.38.83.85/29 brd 70.38.83.87 scope global eth0:5
     inet 70.38.83.86/29 brd 70.38.83.87 scope global eth0:6
     inet6 fe80::21b:21ff:fe28:d515/64 scope link 
        valid_lft forever preferred_lft forever

 # ip route show
 70.38.83.80/29 dev eth0  proto kernel  scope link  src 70.38.83.81 
 70.38.78.160/27 dev eth0  proto kernel  scope link  src 70.38.78.182 
 default via 70.38.78.161 dev eth0 

Desconfigurar todas las IP, menos la principal y una de los alias del archivo /etc/network/interfaces (solo debe quedar eth0 y eth0:1 activas en el HN)

Reiniciar interfaces de red:

 /etc/init.d/networking restart

 # ip addr show
 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
     inet 127.0.0.1/8 scope host lo
     inet6 ::1/128 scope host 
        valid_lft forever preferred_lft forever
 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 10
     link/ether 00:1b:21:28:d5:15 brd ff:ff:ff:ff:ff:ff
     inet 70.38.78.182/27 brd 70.38.78.191 scope global eth0
     inet 70.38.83.81/29 brd 70.38.83.87 scope global eth0:1
     inet6 fe80::21b:21ff:fe28:d515/64 scope link 
        valid_lft forever preferred_lft forever

 apt-get install bridge-utils

 #!/bin/bash
 
 sleep 5
 brctl addbr br0
 ifconfig eth0 0
 brctl addif br0 eth0
 ifconfig br0 70.38.78.182/27
 ifconfig br0:1 70.38.83.81/29
 ip route del default via 70.38.78.161 dev eth0
 ip route add default via 70.38.78.161 dev br0
                                             

Ejecutar script en background. Esto perderá conexion de red y requerirá volver a conectar.

 # ./bridge.sh >/dev/null 2>&1 &
 # exit

Al volver a conectar se creo un bridge:

• La IP principal esta en br0
• Una IP virtual queda en br0:1
• eth0 no tiene IP
• la ruta por defecto está en br0

 # ip addr show
 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
     inet 127.0.0.1/8 scope host lo
     inet6 ::1/128 scope host 
        valid_lft forever preferred_lft forever
 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 10
     link/ether 00:1b:21:28:d5:15 brd ff:ff:ff:ff:ff:ff
     inet6 fe80::21b:21ff:fe28:d515/64 scope link 
        valid_lft forever preferred_lft forever
 3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN 
     link/ether 00:1b:21:28:d5:15 brd ff:ff:ff:ff:ff:ff
     inet 70.38.78.182/27 brd 70.38.78.191 scope global br0
     inet 70.38.83.81/29 brd 70.38.83.87 scope global br0:1
     inet6 fe80::21b:21ff:fe28:d515/64 scope link 
        valid_lft forever preferred_lft forever

 # ip route show
 70.38.83.80/29 dev eth0  proto kernel  scope link  src 70.38.83.81 
 70.38.78.160/27 dev br0  proto kernel  scope link  src 70.38.78.182 
 default via 70.38.78.161 dev br0 

Si todo queda bien, adaptar el /etc/network/interfaces para que esta configuración sea la por defecto:

auto lo
iface lo inet loopback

auto br0
iface br0 inet static
        address 70.38.78.182
        netmask 255.255.255.224
        network 70.38.78.160
        broadcast 70.38.78.191
        gateway 70.38.78.161
        bridge_ports eth0

auto br0:1
iface br0:1 inet static
        address 70.38.83.81
        netmask 255.255.255.248

Se coloca el alias en el bridge.

Reiniciar y ver que todo quede funcionando normalmente.

Ya se puede crear el primer contenedor, sugiendo este documento