A Linux system error after reboot -eth0 no link during initialization

Scenario

A working system was rebooted and it did not come on network after reboot. Service network restart on console display below message.

# service network restart
May 18 23:30:17 bergson kernel: eth1: no link during initialization.
May 18 23:40:43 bergson kernel: eth0: no link during initialization.

Observation

>> ethtool on eth0 and eth1 shows

# ethtool eth0
Speed: Unknown! (6555)
Duplex: Unknown! (255)
Link detected:no

# ethtool eth1
Speed: Unknown! (6555)
Duplex: Unknown! (255)
Link detected:no

>> ifconfig show both NIC are UP

 ifconfig eth0|grep UP

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

 ifconfig eth1|grep UP

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

>> There are other NICs (eth2, eth3) they are suppose to be down and they are down.

Solution

>> Two UP and 2 DOWN NIC have following configuration. eth2 and eth3 were not used , not configured and set ONBOOT=No

/etc/sysconfig/network-scripts/ifcfg-eth0

/etc/sysconfig/network-scripts/ifcfg-eth1

/etc/sysconfig/network-scripts/ifcfg-eth2

/etc/sysconfig/network-scripts/ifcfg-eth3

>> NIC config files were not having HWADDR attribute set.

HWADDR=xx:xx:xx:xx:xx:xx

>> So on reboot, whatever NIC will be scanned first, will become eth0 1 2 3 and so on. So the NIC that was eth0 before reboot, was eth3 after reboot, eth1 -> eth3, eth2 -> eth0, eth3->eth1. So NICs those are suppose to be up, were down. Same way, NICs those are suppose to be down were UP !!

>> Add HWADDR in config file and reboot. This was, a NIC with particular MAC address will always have same device say eth0.

Did it help you ?