CentOS 7 Failed to start LSB: Bring up/down networking

今天用xshell连接虚拟机的时候，突然连接不上，就到虚拟机上去查一下原因，原来是network 启动不了，文档上说要disable NetworkManager, 用 network服务才行。

我用 systemctl network start命令启动时报错：

[root@localhost network-scripts]# systemctl network start
Starting network (via systemctl): Job for network.service failed. See ‘systemctl status network.service’ and ‘journalctl -xn’ for details.[FAILED]
[root@localhost network-scripts]# systemctl status network.service

• LSB: Bring up/down networking Loaded: loaded (/etc/rc.d/init.d/network) Active: failed (Result: exit-code) since Sat 2015-03-07 02:53:12 EST; 6s ago Process: 8596 ExecStart=/etc/rc.d/init.d/network start (code=exited, status=1/FAILURE)Mar 07 02:53:12 localhost.localdomain network[8596]: RTNETLINK answers: File …Mar 07 02:53:12 localhost.localdomain network[8596]: RTNETLINK answers: File …Mar 07 02:53:12 localhost.localdomain network[8596]: RTNETLINK answers: File …Mar 07 02:53:12 localhost.localdomain network[8596]: RTNETLINK answers: File …Mar 07 02:53:12 localhost.localdomain network[8596]: RTNETLINK answers: File …Mar 07 02:53:12 localhost.localdomain network[8596]: RTNETLINK answers: File …Mar 07 02:53:12 localhost.localdomain systemd-sysctl[8913]: Overwriting earli…Mar 07 02:53:12 localhost.localdomain systemd[1]: network.service: control pr…Mar 07 02:53:12 localhost.localdomain systemd[1]: Failed to start LSB: Bring …Mar 07 02:53:12 localhost.localdomain systemd[1]: Unit network.service entere…Hint: Some lines were ellipsized, use -l to show in full.

然后网上搜是因为没加HWADDR…这个我确实给删了…

先看log里说哪个网卡没有UP起来：

[root@localhost network-scripts]# cat /var/log/messages | grep network
Mar 7 03:05:18 localhost kernel: drop_monitor: Initializing network drop monitor serviceMar 7 03:05:19 localhost systemd-udevd[413]: renamed network interface eth1 to enp1s0f1Mar 7 03:05:19 localhost systemd-udevd[416]: renamed network interface eth5 to enp8s0f3Mar 7 03:05:19 localhost systemd-udevd[421]: renamed network interface eth3 to enp8s0f1Mar 7 03:05:19 localhost systemd-udevd[429]: renamed network interface eth4 to enp8s0f2Mar 7 03:05:19 localhost systemd-udevd[411]: renamed network interface eth0 to enp1s0f0Mar 7 03:05:19 localhost systemd-udevd[419]: renamed network interface eth2 to enp8s0f0Mar 7 03:05:25 localhost systemd-udevd[412]: renamed network interface eth1 to enp3s0f1Mar 7 03:05:25 localhost systemd-udevd[414]: renamed network interface eth3 to enp131s0f1Mar 7 03:05:25 localhost systemd-udevd[411]: renamed network interface eth0 to enp3s0f0Mar 7 03:05:25 localhost systemd-udevd[413]: renamed network interface eth2 to enp131s0f0Mar 7 03:05:25 localhost systemd-udevd[415]: renamed network interface eth4 to enp134s0f0Mar 7 03:05:25 localhost systemd-udevd[416]: renamed network interface eth5 to enp134s0f1Mar 7 03:05:30 localhost systemd: Starting Import network configuration from initramfs…Mar 7 03:05:30 localhost systemd: Started Import network configuration from initramfs.Mar 7 03:05:40 localhost systemd: Starting Rollback uncommitted netcf network config change transactions…Mar 7 03:05:40 localhost systemd: Started Rollback uncommitted netcf network config change transactions.Mar 7 03:05:43 localhost systemd: Starting LSB: Bring up/down networking…Mar 7 03:05:45 localhost network: Bringing up loopback interface: [ OK ]Mar 7 03:05:45 localhost network: Bringing up interface br0: ERROR : [/etc/sysconfig/network-scripts/ifup-eth] Device br0 does not seem to be present, delaying initialization.Mar 7 03:05:45 localhost /etc/sysconfig/network-scripts/ifup-eth: Device br0 does not seem to be present, delaying initialization.Mar 7 03:05:45 localhost network: [FAILED]Mar 7 03:05:45 localhost network: Bringing up interface enp1s0f0: [ OK ]Mar 7 03:05:45 localhost network: Bringing up interface enp8s0f0: ERROR : [/etc/sysconfig/network-scripts/ifup-eth] Device does not seem to be present, delaying initialization.Mar 7 03:05:45 localhost /etc/sysconfig/network-scripts/ifup-eth: Device does not seem to be present, delaying initialization.Mar 7 03:05:45 localhost network: [FAILED]Mar 7 03:05:45 localhost network: Bringing up interface enp8s0f1: ERROR : [/etc/sysconfig/network-scripts/ifup-eth] Device does not seem to be present, delaying initialization.Mar 7 03:05:45 localhost /etc/sysconfig/network-scripts/ifup-eth: Device does not seem to be present, delaying initialization.Mar 7 03:05:45 localhost network: [FAILED]Mar 7 03:05:45 localhost systemd: network.service: control process exited, code=exited status=1Mar 7 03:05:45 localhost systemd: Failed to start LSB: Bring up/down networking.Mar 7 03:05:45 localhost systemd: Unit network.service entered failed state.Mar 7 03:05:48 localhost xinetd[1863]: xinetd Version 2.3.15 started with libwrap loadavg labeled-networking options compiled in.

ip addr查看这俩网卡的MAC：

[root@localhost network-scripts]# ip addr
1: lo: mtu 65536 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 valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: enp1s0f0: mtu 1500 qdisc mq master br0 state UP qlen 1000 link/ether 00:25:90:64:a9:30 brd ff:ff:ff:ff:ff:ff inet6 fe80::225:90ff:fe64:a930/64 scope link valid_lft forever preferred_lft forever3: enp1s0f1: mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 00:25:90:64:a9:31 brd ff:ff:ff:ff:ff:ff4: enp8s0f0: mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 00:0c:bd:05:4e:cc brd ff:ff:ff:ff:ff:ff5: enp8s0f1: mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 00:0c:bd:05:4e:cd brd ff:ff:ff:ff:ff:ff6: enp8s0f2: mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 00:0c:bd:05:4e:ce brd ff:ff:ff:ff:ff:ff7: enp8s0f3: mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 00:0c:bd:05:4e:cf brd ff:ff:ff:ff:ff:ff

然后把这俩网卡的mac写到配置文件里：

/etc/sysconfig/network-scripts/ifcfg-enp8s0f0

/etc/sysconfig/network-scripts/ifcfg-enp8s0f1​​

添加：
HWADDR=00:0c:bd:05:4e:cc​

然后重新启动network，就OK啦！

还有一种可能

其实问题不一定是MAC的问题，也有其他的可能性。下面是另一种情况：

虚拟机里边的CentOS7重启之后无法联网了，重启network发现报错。

百度了一圈，都是叫修改mac地址的说法，但是改了之后并没有什么用，最后谷歌解决了。

事实证明百度就是个水货！

解决方式：禁用NetworkManager
下列的命令依次执行：

1. systemctl stop NetworkManager

2. systemctl disable NetworkManager

3. systemctl start network

4. systemctl status network 查看若是显示的是active 那么就是好了

5. 也可以ping 8.8.8.8 试试看 是否成功

然后重启网络服务，能正常联网了！