This Ethernet card error is normally occur on Linux operating system like CentOS, Red Hat Linux etc. When you try to up the Ethernet card it is showing you the above topic error.
So in this post, we will provide you the step by step solutions and troubleshoot all the issue related this error.
In the initial step, you will check which Ethernet card is down , for this you can run the "ifconfig -a" command. Using this command you can check how many internet card is present on the server and on which Ethernet card used IP address.
Let's suppose you are using eth0 on your machine, and if this Ethernet card not taking any ip address and now show on your device that means it is down right now, so please try to start Eth0 device as given below command.
[root@localhost]# ifup eth0
Device eth0 does not seem to be present, delaying initialization
If your internet card show such issue that means you have an issue with MAC address. So in this post I would explain you how to resolve such issue.
1. In this step, please check the MAC Addresses are set correctly or not. For checking this you need to go the network card directory "/etc/sysconfig/network-scripts"
[root@localhost]# cd /etc/sysconfig/network-scripts
[root@localhost]# cat ifcfg-eth0
HWADDR=”00:15:5D:00:91:91”
In the configuration file, you can see the current hardware address of eth0 card, I have show you only HWADDR entry of my eth0 file. In this directory you can see if other Ethernet card is present or not. In my Linux machine i have two Ethernet card , please find the below second Ethernet card MAC address.
[root@localhost]# cat ifcfg-eth1
HWADDR=”00:15:5D:00:91:90”
2. Now we will see which link is present on the system currently and which is not active, for this you can use the below command to check the status.
[root@localhost]# ip -o link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN \ link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000\ link/ether 00:15:5D:00:91:90 brd ff:ff:ff:ff:ff:ff
3: eth2: mtu 1500 qdisc pfifo_fast state UP qlen 1000\ link/ether 00:15:5D:00:91:91 brd ff:ff:ff:ff:ff:ff
Here, no eth1 but there is an eth2 present on the system, so might be problem is that the eth0 is renamed to eth2 but we will confirm with below command.
[root@localhost]# dmesg | grep eth0
udev: renamed network interface eth0 to eth2
udev: renamed network interface rename3 to eth0
From this command it shows that udev rename the network interface, so in the next step we will remove the wrong entry and configure the Ethernet card
3. Now please open the network rules file to confirm the mac address. Please open this file "/etc/udev/rules.d/70-persistent-net.rules"
[root@localhost]# cat /etc/udev/rules.d/70-persistent-net.rules
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:90", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:91", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:91", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
Looks like there are multiple entries for the same MAC address. Removed the incorrect entry and restart the interface using below command.
[root@localhost]# ifup eth0
Now you eth0 card is up and if you are running "ifconfig -a" command you can see the eth0 card with mac address.
