前言

刚手动在vmware14中装完centos6.9-minimal-64bits,ifconfig是没IP的.
将/etc/sysconfig/network-scripts/ifcfg-eth0中的ONBOOT由no改为yes,增加DNS服务器，重启网卡服务，IP就有了。

实验

刚装完centos6.9-minimal-64bits,/etc/udev/rules.d/70-persistent-net.rules 文件不用改,就一块网卡

cd /etc/sysconfig/network-scripts
mkdir ./bk
cp ./ifcfg-eth0 ./bk

vi ./ifcfg-eth0

#--------------------------------------------------------------------------------
# @file /etc/sysconfig/network-scripts/ifcfg-eth0
#--------------------------------------------------------------------------------
DEVICE=eth0
TYPE=Ethernet
UUID=ed4384a7-1ab2-4720-bb0b-9fe15d6289f3

# change no to yes
ONBOOT=yes

NM_CONTROLLED=yes
BOOTPROTO=dhcp
HWADDR=00:0C:29:D7:31:51
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"

# add dns server
DNS1=8.8.8.8
DNS2=8.8.4.4
#--------------------------------------------------------------------------------

service network restart

[root@localhost ~]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0C:29:D7:31:51  
          inet addr:192.168.180.136  Bcast:192.168.180.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fed7:3151/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:110 errors:0 dropped:0 overruns:0 frame:0
          TX packets:65 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:10767 (10.5 KiB)  TX bytes:8445 (8.2 KiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)