4、每次重启网卡，总是提示
　　Active connection path: /org/freedesktop/NetworkManager/ActiveConnection/9
　　此时网卡也可以正常通信，这个是因为RedHat自己开发的NetworkManager管理工具和/etc/sysconfig/network-scripts/ifcfg-ethx配置不同步造成的。
　　解决方法：
　　要消除这个提示，请关闭NetworkManager服务即可：
[root@rac01 ~]# service network restart
Shutting down loopback interface:                        [  OK  ]
Bringing up loopback interface:                            [  OK  ]
Bringing up interface eth0:  Active connection state: activated
Active connection path: /org/freedesktop/NetworkManager/ActiveConnection/2   [  OK  ]
Bringing up interface eth1:  Active connection state: activated
Active connection path: /org/freedesktop/NetworkManager/ActiveConnection/3   [  OK  ]
　　关闭NetworkManager服务
　　[root@rac01 ~]# service NetworkManager stop
　　Stopping NetworkManager daemon:                            [  OK  ]
　　再次重启网卡
　　[root@rac01 ~]# service network restart
　　Shutting down loopback interface:                     [  OK  ]
　　Bringing up loopback interface:                          [  OK  ]
　　Bringing up interface eth0:                                [  OK  ]
　　Bringing up interface eth1:                                [  OK  ]
　　5、重启网卡出现提示：
　　Bringing up interface eth0:  Determining if ip address 10.109.67.81 is already in use for device eth0...
　　[  OK  ]
　　Bringing up interface eth1:  Determining if ip address 10.109.67.83 is already in use for device eth1...
　　[  OK  ]
　　该警告一般是由于网卡解析arp协议导致的，可在网卡的配置文件中加入ARPCHECK=NO参数来屏蔽该检查
[root@rac01 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=none
IPADDR=10.109.67.81
PREFIX=24
GATEWAY=10.109.67.254
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME=eth0
UUID=86d44060-4579-48cc-b85b-219a206ca37c
ONBOOT=yes
HWADDR=00:50:56:95:09:76
LAST_CONNECT=1411004329
ARPCHECK=no
　　再次启动网卡，一切正常
　　[root@rac01 ~]# service network restart
　　Shutting down interface eth0:                              [  OK  ]
　　Shutting down interface eth1:                              [  OK  ]
　　Shutting down loopback interface:                          [  OK  ]
　　Bringing up loopback interface:                            [  OK  ]
　　Bringing up interface eth0:                                [  OK  ]
　　Bringing up interface eth1:                                [  OK  ]