Acontece que o motivo não estava relacionado a /etc/network/interfaces
. Essa máquina era uma VM Vagrant , que por padrão tem algumas coisas extras em /etc/rc.local
:
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
# Make sure eth0 is working. This works around Vagrant issue #391
dhclient eth0
exit 0
Comente a linha dhclient eth0
e reinicialize os rendimentos:
vagrant@precise64:~$ ip r
default via 10.0.0.1 dev eth1 metric 100
10.0.0.0/24 dev eth1 proto kernel scope link src 10.0.0.99
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15