執行ifconfig eth2 up命令報錯eth2: unknown interface: No such device的解決思路

排查問題思路

一般出現這種狀況都是網卡mac地址錯誤引起的！要么網卡配置文件中的mac地址不對，要么/etc/udev/rules.d/70-persistent-net.rules文件中的mac地址不對！！！

問題現象描述

• bond網卡地址ping不通；
• 交換機側看對應端口狀態如下(無關信息省略)

<CL202-R04F02-H3CS7610-SW01>display interface Ten-GigabitEthernet 1/2/0/4
Ten-GigabitEthernet1/2/0/4
Current state: UP
Line protocol state: UP
IP packet frame type: Ethernet II, hardware address: 7057-bf25-8a00
......

<CL202-R04F02-H3CS7610-SW01>display interface Ten-GigabitEthernet 2/2/0/4
Ten-GigabitEthernet2/2/0/4
Current state: UP
Line protocol state: DOWN(LAGG)
IP packet frame type: Ethernet II, hardware address: 7057-bf24-b800
......

• 在配置bond的兩張網卡上執行ifconfig eth2 up和ifconfig eth3 up都報類似的錯：eth2: unknown interface: No such device；

故障分析定位

• 從故障現象描述第3條手動UP網卡的報錯信息以及交換機側看對應端口的信息，基本可以排除是交換機側的故障和物理鏈路故障，主要排查服務器側的故障；一般此問題是服務器網卡的MAC地址不對造成的。

故障排查過程

• 查看網卡
  如下，我們可以看到系統中有4張網卡，eth0、eth1、eth2和eth3：

[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# ll ifcfg-*
-rw-r--r--. 1 root root 196 Mar 23 15:34 ifcfg-bond0
-rw-r--r--  1 root root 328 Mar 23 21:02 ifcfg-eth0
-rw-r--r--. 1 root root 212 Mar 23 15:30 ifcfg-eth1
-rw-r--r--  1 root root 117 May  7 16:58 ifcfg-eth2
-rw-r--r--  1 root root 117 May  7 16:58 ifcfg-eth3
-rw-r--r--. 1 root root 254 Apr 27  2018 ifcfg-lo
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# 

• 查看/etc/udev/rules.d/70-persistent-net.rules文件內容如下

[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# more /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 0x8086:0x1521 (igb)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="50:af:73:2e:5c:37", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

# PCI device 0x8086:0x1521 (igb)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="50:af:73:2e:5c:38", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

# PCI device 0x8086:0x37d3 (i40e)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="6c:92:bf:c5:a8:28", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"

# PCI device 0x8086:0x37d3 (i40e)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="6c:92:bf:c5:a8:29", ATTR{type}=="1", KERNEL=="eth*", NAME="eth3"

# PCI device 0x8086:0x37d3 (i40e)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="6c:92:bf:a3:ac:49", ATTR{type}=="1", KERNEL=="eth*", NAME="eth4"

# PCI device 0x8086:0x37d3 (i40e)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="6c:92:bf:a3:ac:48", ATTR{type}=="1", KERNEL=="eth*", NAME="eth5"
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]#

• 發現的問題：在網卡配置文件目錄下只有eth0、eth1、eth2和eth3這4張網卡，但是在/etc/udev/rules.d/70-persistent-net.rules文件中發現竟然多了eth4和eth5這2張網卡；並且查看eth2和eth3網卡配置文件時發現其mac地址和/etc/udev/rules.d/70-persistent-net.rules文件中顯示的eth2和eth3文件的mac地址不一樣；eth2和eth3配置文件內容如下：

[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# cat ifcfg-eth2 
DEVICE="eth2"
#HWADDR="6c:92:bf:c5:a8:28"
ONBOOT=yes
BOOTPROTO=none
TYPE=Ethernet
NAME="eth2"
MASTER=bond0
SLAVE=yes
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# 
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# cat ifcfg-eth3
DEVICE="eth3"
#HWADDR="6c:92:bf:c5:a8:29"
ONBOOT=yes
BOOTPROTO=none
TYPE=Ethernet
NAME="eth3"
MASTER=bond0
SLAVE=yes
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# 

• 可以從以上信息看出，eth2和eth3網卡配置文件中的mac地址和/etc/udev/rules.d/70-persistent-net.rules中eth2和eth3中的mac地址不一樣；

• 遠程登錄IPMI查看主機mac地址信息如下圖：
  

• 從上述信息可以判定配置文件中eth2和eth3的mac地址信息是錯的

造成mac地址錯誤的原因

之前這台設備報修過，更換過網卡文件，所以網卡的mac地址變了；但是/etc/udev/rules.d/70-persistent-net.rules和網卡配置文件中eth2和eth3的mac地址沒有對應更新，而是異常新增了並不存在的eth4和eth5網卡，而實際的bond配置還是使用的eth2和eth3網卡，所以網絡異常，手動UP網卡報錯unknown interface: No such device。

解決辦法

修改網卡配置文件和/etc/udev/rules.d/70-persistent-net.rules，修改后正確配置如下：

• /etc/udev/rules.d/70-persistent-net.rules

[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# cat /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 0x8086:0x1521 (igb)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="50:af:73:2e:5c:37", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

# PCI device 0x8086:0x1521 (igb)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="50:af:73:2e:5c:38", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

# PCI device 0x8086:0x37d3 (i40e)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="6c:92:bf:a3:ac:48", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"

# PCI device 0x8086:0x37d3 (i40e)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="6c:92:bf:a3:ac:49", ATTR{type}=="1", KERNEL=="eth*", NAME="eth3"
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# 

• ifcfg-eth2

[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# cat ifcfg-eth2 
DEVICE="eth2"
#HWADDR="6c:92:bf:a3:ac:48"
ONBOOT=yes
BOOTPROTO=none
TYPE=Ethernet
NAME="eth2"
MASTER=bond0
SLAVE=yes
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# 

• ifcfg-eth3

[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# cat ifcfg-eth3
DEVICE="eth3"
#HWADDR="6c:92:bf:a3:ac:49"
ONBOOT=yes
BOOTPROTO=none
TYPE=Ethernet
NAME="eth3"
MASTER=bond0
SLAVE=yes
[root@CL202-R04F05-NRGL-MONGODB-SLAVE-NF5180M5-SV01 network-scripts]# 

關鍵最后一步 --- 重啟主機

修改配置文件后，嘗試過重啟網卡，但是依舊未成功，所以嘗試了重啟主機后世界豁然開朗，網絡馬上ojbk。
注：沒修改mac地址之前重啟網卡也是無效的。