故障：在HP 785G6（服務器有2個集成網卡，4個獨立網卡）上裝CentOS6.5後配置網卡信息後，重啟網卡報錯，提示Bringing uo interface eth0:bnx2 0000:02:03.0:etho:register_cnicfailed Determining if ip address isalready in use for device eth0，網絡不通，截圖如下
排查經過：查看配置文件，
[root@HGJ0205 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0沒有問題，
查看網卡
[root@HGJ0205 ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:26:55:DF:DD:9E
inet addr:10.12.5.103 Bcast:10.12.5.255 Mask:255.255.255.0
inet6 addr: fe80::226:55ff:fedf:dd9e/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4885599 errors:0 dropped:0 overruns:0 frame:0
TX packets:5632499 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1460799376 (1.3 GiB) TX bytes:2154273766 (2.0 GiB)
Interrupt:30 Memory:fdce0000-fdd00000
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:16436 Metric:1
RX packets:7752962 errors:0 dropped:0 overruns:0 frame:0
TX packets:7752962 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3827246039 (3.5 GiB) TX bytes:3827246039 (3.5 GiB)
網卡啟動，已經配置了ip,沒有問題，檢查網關
[root@HGJ0205 ~]# ping 10.12.5.1
發現自己的網關也ping不同。
檢查網線狀況，發現網線不在集成網卡eth0上，而是在獨立配置的網卡上，從而導致配置好網卡信息不是插網線的網卡，也就是說插網線的網卡沒有網卡信息，所以不通。
[root@HGJ0205 ~]#cat /etc/udev/rules.d/70-persistent-net.rules
# This file was automatically generated bythe /lib/udev/write_net_rules
# program, run by thepersistent-net-generator.rules rules file.
#
# You can modify it, as long as you keepeach rule on a single
# line, and change only the value of theNAME= key.
# PCI device 0x8086:0x105e (e1000e) (customname provided by external tool)
SUBSYSTEM=="net",ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:26:55:df:dd:9f",ATTR{type}=="1", KERNEL=="eth*", NAME="eth3"
# PCI device 0x8086:0x105e (e1000e) (customname provided by external tool)
SUBSYSTEM=="net",ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:26:55:e0:35:ef",ATTR{type}=="1", KERNEL=="eth*", NAME="eth5"
# PCI device 0x14e4:0x164a (bnx2)
SUBSYSTEM=="net",ACTION=="add", DRIVERS=="?*", ATTR{address}=="78:e7:d1:fb:6e:38", ATTR{type}=="1",KERNEL=="eth*", NAME="eth1"
# PCI device 0x8086:0x105e (e1000e) (customname provided by external tool)
SUBSYSTEM=="net",ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:26:55:df:dd:9e",ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"
# PCI device 0x14e4:0x164a (bnx2) (customname provided by external tool)
SUBSYSTEM=="net",ACTION=="add", DRIVERS=="?*", ATTR{address}=="78:e7:d1:fb:6e:3a", ATTR{type}=="1",KERNEL=="eth*", NAME="eth1"
# PCI device 0x8086:0x105e (e1000e) (customname provided by external tool)
SUBSYSTEM=="net",ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:26:55:e0:35:ee",ATTR{type}=="1", KERNEL=="eth*", NAME="eth4"
6個網卡，看著都頭暈。
解決方案：既然找到問題解決它。只要把網線接口對應的配置文件配置好久可以，兩個解決方案
一、配置好一個網絡配置文件，然後把網線一個網口一個網口的測試，通了就說明是這個網卡的。
二、網線不動，一個一個配置所有的網卡，哪個通了也說明是對了
注意：1、千萬不要把所有的網卡都配置了測試，ip會沖突。
2、集成網卡和獨立網卡的mac地址格式是不一樣的，這樣可以很快的分辨出你配置的是哪個網卡，紅色的是集成網卡的，減少排查步驟。
更多CentOS相關信息見CentOS 專題頁面 http://www.linuxidc.com/topicnews.aspx?tid=14
