CentOS 7中没有ifconfig命令，而且不能发现eth0

1、由于安装时使用的是最小化安装CentOS 7,安装完成后没有发现ifconfig命令

检查/sbin下也没有这个命令。使用的是root身份。

#yum install -y net-tools\*

可以成功安装ifconfig

[root@localhost~]#ls/sbin/if*
/sbin/ifcfg/sbin/ifconfig/sbin/ifdown/sbin/ifenslave/sbin/ifstat/sbin/ifup

2、安装过程中没有提示设置网卡，安装好后也没有发现ifcfg-eth0的 配置文件。

[root@localhost~]#ls/etc/sysconfig/network-scripts/
ifcfg-eno16777736ifdown-ibifdown-pppifdown-tunnelifup-ibifup-plusbifup-Teamnetwork-functions
ifcfg-loifdown-ipppifdown-routesifupifup-ipppifup-postifup-TeamPortnetwork-functions-ipv6
ifdownifdown-ipv6ifdown-sitifup-aliasesifup-ipv6ifup-pppifup-tunnel
ifdown-bnepifdown-isdnifdown-Teamifup-bnepifup-isdnifup-routesifup-wireless
ifdown-ethifdown-postifdown-TeamPortifup-ethifup-plipifup-sitinit.ipv6-global

使用dmesg | grep -in eth检查开机信息中有没有eth0的消息

[root@localhost~]#dmesg|grep-ineth
1688:[1.850428]e10000000:02:01.0eth0:(PCI:66MHz:32-bit)00:0c:29:41:57:0b
1689:[1.850433]e10000000:02:01.0eth0:Intel(R)PRO/1000NetworkConnection

发现由interface eth0改为了eno16777736

3、更改网卡的名字 - 由eno16777736改为eth0

[root@localhost~]#vim/etc/default/grub
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed's,release.*$,g'/etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="net.ifnames=0crashkernel=autord.lvm.lv=centos/rootrd.lvm.lv=centos/swaprhgbquiet"
GRUB_DISABLE_RECOVERY="true"

修改grub中的GRUB_CMDLINE_LINUX，追加语句"net.ifnames=0 “。

然后执行# grub2-mkconfig -o /etc/grub2.cfg

之后重启# reboot

[root@localhost~]#grub2-mkconfig-o/etc/grub2.cfg
Generatinggrubconfigurationfile...
Foundlinuximage:/boot/vmlinuz-3.10.0-327.el7.x86_64
Foundinitrdimage:/boot/initramfs-3.10.0-327.el7.x86_64.img
Foundlinuximage:/boot/vmlinuz-0-rescue-4e4bd6a60e2f4848aa19b757b0d96522
Foundinitrdimage:/boot/initramfs-0-rescue-4e4bd6a60e2f4848aa19b757b0d96522.img
done
[root@localhost~]#reboot

再查看网卡，发现名字已经更改过来了。

[root@localhost~]#ifconfig
eth0:flags=4163<UP,BROADCAST,RUNNING,MULTICAST>mtu1500
inet192.168.1.124netmask255.255.255.0broadcast192.168.1.255
inet6fe80::20c:29ff:fe41:570bprefixlen64scopeid0x20<link>
ether00:0c:29:41:57:0btxqueuelen1000(Ethernet)
RXpackets124bytes13087(12.7KiB)
RXerrors0dropped0overruns0frame0
TXpackets68bytes9617(9.3KiB)
TXerrors0dropped0overruns0carrier0collisions0

lo:flags=73<UP,LOOPBACK,RUNNING>mtu65536
inet127.0.0.1netmask255.0.0.0
inet6::1prefixlen128scopeid0x10<host>
looptxqueuelen0(LocalLoopback)
RXpackets4bytes344(344.0B)
RXerrors0dropped0overruns0frame0
TXpackets4bytes344(344.0B)
TXerrors0dropped0overruns0carrier0collisions0

但是仍需要将/etc/sysconfig/network-scripts/ifcfg-eno16777736更名为ifcfg-eth0,同时修改其内容，指定IP、NETMASK及GATEWAY，同时修改onboot=no为yes。最后执行service restart network。

[root@localhost~]#cp-aifcfg-eno16777736ifcfg-eth0