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I have classroom full of computer running CentOS 7 and only one computer can't get IPv4 address from DHCP server during boot, because NIC is not yet up, when dhcp client tries to get IPv4 address from DHCP server. Here is output of /var/log/messages:

Oct 14 14:15:03 a302 network: [  OK  ]
Oct 14 14:15:03 a302 network: Activating interface enp0s25:
Oct 14 14:15:04 a302 kernel: IPv6: ADDRCONF(NETDEV_UP): enp0s25: link is not ready
...
Oct 14 14:15:09 a302 network: Determining IP information for enp0s25 ... failed; missing links. Is the cable OK?
Oct 14 14:15:09 a302 network: [FAILED]

When NIC becomes ready, then it gets at least IPv6 address:

Oct 14 14:15:19 a302 kernel: e1000e: enp0s25 NIC Link is Up 100 Mbps Full Duplex, Flow Control: None
Oct 14 14:15:19 a302 kernel: e1000e 0000:00:19.0 enp0s25: Link Speed was downgraded by SmartSpeed
Oct 14 14:15:19 a302 kernel: e1000e 0000:00:19.0 enp0s25: 10/100 speed: disabling TSO
Oct 14 14:15:19 a302 kernel: IPv6: ADDRCONF(NETDEV_CHANGE): enp0s25: link becomes ready
Oct 14 14:15:19 a302 NetworkManager[938]: <info> (enp0s25): link connected
Oct 14 14:15:20 a302 avahi-daemon[770]: Registering new address record for fe80::223:aeff:fea4:76d3 on enp0s25.*.
Oct 14 14:15:21 a302 avahi-daemon[770]: Registering new address record for 2001:718:1c01:72:223:aeff:fea4:76d3 on enp0s25.*.
Oct 14 14:15:21 a302 avahi-daemon[770]: Withdrawing address record for fe80::223:aeff:fea4:76d3 on enp0s25.

The content of /etc/sysconfig/network-scripts/ifcfg-enp0s25 is following:

# Generated by dracut initrd
DEVICE="enp0s25"
ONBOOT=yes
NETBOOT=yes
UUID="c2ed9174-ece7-4bea-9da4-0123456789ab"
IPV6INIT=yes
BOOTPROTO=dhcp
HWADDR="00:23:ae:11:22:33"
TYPE=Ethernet
NAME="enp0s25"
NM_CONTROLLED=no
IPV4_FAILURE_FATAL=yes

Other computers in classroom gets IPv4 address without any problem.

Edit: problem was in the UTP cable. There were one wrong pair of wires.

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    IPv6 may be a red herring as it can self-assign. Have you checked the cable like it says? Swap it for one in a working machine - just the nic end, leave the other end as is, you only want to change one thing at at ime.
    – Paul
    Oct 17, 2014 at 13:08
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    What happens when you run (as root) dhclient enp0s25 ? Oct 17, 2014 at 13:10
  • Hi, first time CentOS7 user here. @garethTheRed, 'dhclient enp0s25' works from my side...thanks a lot :)
    – icasimpan
    Oct 13, 2016 at 6:28

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