Minha dica vem do rastreamento de pilha no link . Veja o comentário # 1. Você pode ver abaixo /etc/network/interfaces
then /etc/network/interfaces.d
.
read_interfaces_defn(..., '/etc/network/interfaces'
Reading directory /etc/network/interfaces.d
Parsing file eth0
read_interfaces_defn(..., 'eth0') failed in directory '/root'
Parsing file eth1
read_interfaces_defn(..., 'eth1') failed in directory '/root'
Parsing file eth2
read_interfaces_defn(..., 'eth2') failed in directory '/root'
Parsing file eth3
read_interfaces_defn(..., 'eth3') failed in directory '/root'
Parsing file eth4
read_interfaces_defn(..., 'eth4') failed in directory '/root'
Parsing file lo
read_interfaces_defn(..., 'lo') failed in directory '/root'
run-parts --verbose /etc/network/if-pre-up.d
run-parts --verbose /etc/network/if-up.d
run-parts: executing /etc/network/if-up.d/000resolvconf
run-parts: executing /etc/network/if-up.d/ntpdate
run-parts: executing /etc/network/if-up.d/postfix
run-parts: executing /etc/network/if-up.d/upstart
Além do rastreamento de pilha aqui link , você pode ver que ele vai reclamar por duplicatas.
/etc/network/interfaces:17: duplicate interface
ifup: couldn't read interfaces file "/etc/network/interfaces"