问题描述：准备用RedHat6.5安装Oracle 12c RAC，系统环境准备好后发现，新版本的RedHat网卡配置跟以前不大一样，总结问题与解决方法如下：
1、找不到eth0文件
在使用RedHat6.5，新装好的系统，发现没有eth0网卡，默认的第一个网卡是Auto-eth0
[root@rac01 ~]# cat /etc/sysconfig/network-scripts/ifcfg-Auto_eth0
TYPE=Ethernet
BOOTPROTO=none
IPADDR=10.10.10.110
PREFIX=24
GATEWAY=10.10.10.111
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
解决方法：
直接更名ifcfg-Auto_eth0文件为eth0，重启网卡后会发现，网卡名已经变为eth0
[root@rac01 ~]# service network restart
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: Active connection state: activated
2、ifconfig 发现网卡服务名并未更改
[root@rac01 ~]# ifconfig
Auto_eth0 Link encap:Ethernet HWaddr 00:50:56:95:09:76
inet addr:10.10.10.110 Bcast:10.10.10.111 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fe95:976/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:484 errors:0 dropped:0 overruns:0 frame:0
TX packets:57 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:40095 (39.1 KiB) TX bytes:6271 (6.1 KiB)
解决方法：
每次更改RedHat的网卡信息，RedHat会自动的将网卡的MAC地址和对应的网卡服务名关系记录在/etc/udev/rules.d/70-persistent-net.rules中，修改里面的对应服务名即可
[root@rac01 ~]# vim /etc/udev/rules.d/70-persistent-net.rules
# This file was automatically generated by the /lib/udev/write_net_rules
# program, run by the persistent-net-generator.rules rules file.
#
# You can modify it, as long as you keep each rule on a single
# line, and change only the value of the NAME= key.
# PCI device 0x15ad:0x07b0 (vmxnet3)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:29:1e:f6:ad", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
修改完成后需重启一下系统，再次查看网卡服务名已经更改
[root@rac01 ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:56:95:09:76
inet addr:10.109.67.81 Bcast:10.109.67.255 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fe95:976/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:985 errors:0 dropped:0 overruns:0 frame:0
TX packets:61 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:74395 (72.6 KiB) TX bytes:6527 (6.3 KiB)
3、网卡eth0被删除后，新加的网卡成了eth1，如何让从eth0开始
[root@rac01 ~]# ifconfig
eth1 Link encap:Ethernet HWaddr 00:50:56:95:09:76
inet addr:10.10.10.110 Bcast:10.10.10.111 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fe95:976/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:830 errors:0 dropped:0 overruns:0 frame:0
TX packets:57 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:63700 (62.2 KiB) TX bytes:6259 (6.1 KiB)
eth2 Link encap:Ethernet HWaddr 00:0C:29:1E:F6:B7
inet addr:10.10.10.120 Bcast:10.10.10.111Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe1e:f6b7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:777 errors:0 dropped:0 overruns:0 frame:0
TX packets:11 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:54938 (53.6 KiB) TX bytes:746 (746.0 b)
解决方法：
同2问题类似，即可以手动的修改70-persistent-net.rules文件，将对应的MAC地址与网卡序号改成想要的，也可以直接删除该文件，重启系统后，RedHat会自动的创建该文件，并从0开始计数。
删除文件，重启系统
[root@rac01 ~]# mv /etc/udev/rules.d/70-persistent-net.rules /etc/udev/rules.d/7
0-persistent-net.rules.bak
[root@rac01 ~]# reboot
再次查看，会发现已经从eht0开始
[root@rac01 ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:56:95:09:76
inet addr:10.109.67.81 Bcast:10.109.67.255 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fe95:976/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:206 errors:0 dropped:0 overruns:0 frame:0
TX packets:68 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:19282 (18.8 KiB) TX bytes:7215 (7.0 KiB)
eth1 Link encap:Ethernet HWaddr 00:0C:29:1E:F6:B7
inet addr:10.109.67.83 Bcast:10.109.67.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe1e:f6b7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:131 errors:0 dropped:0 overruns:0 frame:0
TX packets:11 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8736 (8.5 KiB) TX bytes:746 (746.0 b)
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 ]