https://www.cnblogs.com/bonjov1/p/4323836.html CentOS7 Failed to start LSB: Bring up/down networking.解决方法 今天用CentOS7 RDO方式安装Openstack，文档上说要disable NetworkManager, 用 network服务才行。 但是我用 service network start命令启动时报错： [root@localhost network-scripts]# service network start Starting network (via systemctl): Job -- :: EST; 6s ago Process: ExecStart=/etc/rc.d/init.d/network start (code=exited, status=/FAILURE)Mar :: localhost.localdomain network[]: RTNETLINK answers: File ...Mar :: localhost.localdomain network[]: RTNETLINK answers: File ...Mar :: localhost.localdomain network[]: RTNETLINK answers: File ...Mar :: localhost.localdomain network[]: RTNETLINK answers: File ...Mar :: localhost.localdomain network[]: RTNETLINK answers: File ...Mar :: localhost.localdomain network[]: RTNETLINK answers: File ...Mar :: localhost.localdomain systemd-sysctl[]: Overwriting earli...Mar :: localhost.localdomain systemd[]: network.service: control pr...Mar :: localhost.localdomain systemd[]: Failed to start LSB: Bring ...Mar :: localhost.localdomain systemd[]: 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 :: localhost kernel: drop_monitor: Initializing network drop monitor serviceMar :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd-udevd[]: renamed network :: localhost systemd: Starting Import network configuration :: localhost systemd: Started Import network configuration :: localhost systemd: Starting Rollback uncommitted netcf network config change transactions...Mar :: localhost systemd: Started Rollback uncommitted netcf network config change transactions.Mar :: localhost systemd: Starting LSB: Bring up/down networking...Mar :: localhost network: Bringing up loopback :: localhost network: Bringing up :: localhost /etc/sysconfig/network-scripts/ifup-eth: Device br0 does not seem to be present, delaying initialization.Mar :: localhost network: [FAILED]Mar :: localhost network: Bringing up :: localhost network: Bringing up :: localhost /etc/sysconfig/network-scripts/ifup-eth: Device does not seem to be present, delaying initialization.Mar :: localhost network: [FAILED]Mar :: localhost network: Bringing up :: localhost /etc/sysconfig/network-scripts/ifup-eth: Device does not seem to be present, delaying initialization.Mar :: localhost network: [FAILED]Mar :: localhost systemd: network.service: control process exited, code=exited status=1Mar :: localhost systemd: Failed to start LSB: Bring up/down networking.Mar :: localhost systemd: Unit network.service entered failed state.Mar :: localhost xinetd[]: xinetd Version 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 : lo: mtu qdisc noqueue state UNKNOWN link/loopback ::::: brd ::::: inet scope host lo valid_lft forever preferred_lft forever inet6 ::/ scope host valid_lft forever preferred_lft forever2: enp1s0f0: mtu qdisc mq master br0 state UP qlen link/ether ::::a9: brd ff:ff:ff:ff:ff:ff inet6 fe80:::90ff:fe64:a930/ scope link valid_lft forever preferred_lft forever3: enp1s0f1: mtu qdisc noop state DOWN qlen link/ether ::::a9: brd ff:ff:ff:ff:ff:ff4: enp8s0f0: mtu qdisc noop state DOWN qlen link/ether :0c:bd::4e:cc brd ff:ff:ff:ff:ff:ff5: enp8s0f1: mtu qdisc noop state DOWN qlen link/ether :0c:bd::4e:cd brd ff:ff:ff:ff:ff:ff6: enp8s0f2: mtu qdisc noop state DOWN qlen link/ether :0c:bd::4e:ce brd ff:ff:ff:ff:ff:ff7: enp8s0f3: mtu qdisc noop state DOWN qlen link/ether :0c:bd::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=:0c:bd::4e:cc 然后重新启动network，就OK啦！ 很久没更新了，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 . systemctl stop NetworkManager . systemctl disable NetworkManager 然后重启网络服务，能正常联网了！