查看/var/log/message
Jun 5 00:58:25 root systemd: Started Network Manager. Jun 5 00:58:25 root systemd: Starting LSB: Bring up/down networking... Jun 5 00:58:25 root kernel: IPv6: ADDRCONF(NETDEV_UP): em1: link is not ready Jun 5 00:58:25 root kernel: IPv6: ADDRCONF(NETDEV_UP): em1: link is not ready Jun 5 00:58:25 root NetworkManager[1536]: <info> (em1): preparing device Jun 5 00:58:25 root NetworkManager[1536]: <info> read connection 'Wired connection 1' Jun 5 00:58:25 root NetworkManager[1536]: <info> (em1): created default wired connection 'Wired connection 1' Jun 5 00:58:25 root NetworkManager[1536]: <info> (em2): carrier is OFF Jun 5 00:58:25 root NetworkManager[1536]: <info> (em2): new Ethernet device (driver: 'tg3' ifindex: 3) Jun 5 00:58:25 root NetworkManager[1536]: <info> (em2): exported as /org/freedesktop/NetworkManager/Devices/2 Jun 5 00:58:25 root NetworkManager[1536]: <info> (em2): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Jun 5 00:58:25 root kernel: IPv6: ADDRCONF(NETDEV_UP): em2: link is not ready Jun 5 00:58:25 root kernel: IPv6: ADDRCONF(NETDEV_UP): em2: link is not ready Jun 5 00:58:25 root NetworkManager[1536]: <info> (em2): preparing device Jun 5 00:58:25 root NetworkManager[1536]: <info> (em3): carrier is OFF Jun 5 00:58:25 root NetworkManager[1536]: <info> (em3): new Ethernet device (driver: 'tg3' ifindex: 4) Jun 5 00:58:25 root NetworkManager[1536]: <info> (em3): exported as /org/freedesktop/NetworkManager/Devices/3 Jun 5 00:58:25 root NetworkManager[1536]: <info> (em3): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Jun 5 00:58:25 root kernel: IPv6: ADDRCONF(NETDEV_UP): em3: link is not ready Jun 5 00:58:25 root kernel: IPv6: ADDRCONF(NETDEV_UP): em3: link is not ready Jun 5 00:58:25 root NetworkManager[1536]: <info> (em3): preparing device Jun 5 00:58:25 root NetworkManager[1536]: <info> (em4): carrier is OFF Jun 5 00:58:25 root NetworkManager[1536]: <info> (em4): new Ethernet device (driver: 'tg3' ifindex: 5) Jun 5 00:58:25 root NetworkManager[1536]: <info> (em4): exported as /org/freedesktop/NetworkManager/Devices/4 Jun 5 00:58:25 root NetworkManager[1536]: <info> (em4): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Jun 5 00:58:25 root kernel: IPv6: ADDRCONF(NETDEV_UP): em4: link is not ready Jun 5 00:58:26 root kernel: IPv6: ADDRCONF(NETDEV_UP): em4: link is not ready Jun 5 00:58:26 root NetworkManager[1536]: <info> (em4): preparing device Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p1): carrier is OFF Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p1): new Ethernet device (driver: 'bnx2x' ifindex: 6) Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p1): exported as /org/freedesktop/NetworkManager/Devices/5 Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p1): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Jun 5 00:58:26 root kernel: IPv6: ADDRCONF(NETDEV_UP): p4p1: link is not ready Jun 5 00:58:26 root rc.local: Unlinking stale socket /etc/supervisor.sock Jun 5 00:58:26 root dracut: dracut- Jun 5 00:58:26 root kernel: bnx2x 0000:82:00.0 p4p1: using MSI-X IRQs: sp 143 fp[0] 145 ... fp[7] 152 Jun 5 00:58:26 root dracut: Executing: /usr/sbin/dracut --hostonly --hostonly-cmdline -o "plymouth dash resume" -f /boot/initramfs-3.10.0-229.el7.x86_64kdump.img 3.10.0-229.el7.x86_64 Jun 5 00:58:26 root systemd: Started Dynamic System Tuning Daemon. Jun 5 00:58:26 root rc.local: SIOCADDRT: Network is unreachable Jun 5 00:58:26 root kernel: IPv6: ADDRCONF(NETDEV_UP): p4p1: link is not ready Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p1): preparing device Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p2): carrier is OFF Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p2): new Ethernet device (driver: 'bnx2x' ifindex: 7) Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p2): exported as /org/freedesktop/NetworkManager/Devices/6 Jun 5 00:58:26 root NetworkManager[1536]: <info> (p4p2): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Jun 5 00:58:26 root rc.local: SIOCADDRT: Network is unreachable Jun 5 00:58:26 root systemd: rc-local.service: control process exited, code=exited status=7 Jun 5 00:58:26 root systemd: Failed to start /etc/rc.d/rc.local Compatibility. Jun 5 00:58:26 root systemd: Unit rc-local.service entered failed state.
打开/etc/rc.local看是否有其它的任务或者开关导致启动失败。如果有就看需要去除