debian8 系统，网卡不能自动启动。
/etc/network/interfaces的配置也对：
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.1.188
netmask 255.255.255.0
gateway 192.168.1.2
使用systemctl status networking.service 查看网卡服务状态时，显示：
7月 15 12:08:01 hnhnlp1 networking[2636]: process and the information we find helpful for debugging..
7月 15 12:08:01 hnhnlp1 networking[2636]: exiting.
7月 15 12:08:01 hnhnlp1 networking[2636]: Failed to bring up eth0.
7月 15 12:08:01 hnhnlp1 networking[2636]: RTNETLINK answers: Operation not permitted
7月 15 12:08:01 hnhnlp1 networking[2636]: Failed to bring up eth1.
7月 15 12:08:01 hnhnlp1 networking[2636]: RTNETLINK answers: Operation not permitted
7月 15 12:08:01 hnhnlp1 networking[2636]: Failed to bring up eth2.
7月 15 12:08:01 hnhnlp1 networking[2636]: /etc/network/if-up.d/mountnfs: 17: /etc/network/if-up.d/mountnfs: systemctl: Permission denied
7月 15 12:08:01 hnhnlp1 networking[2636]: done.
7月 15 12:08:01 hnhnlp1 systemd[1]: Started LSB: Raise network interfaces..
虽然不能自动激活，但是手动输入if-up eth0却能手动激活。
