I was playing with My Virtualbox today and i tried to clone some Centos Servers. But after this, when starting the eth0, it is no more available.

check network:

Mã:
# ifconfig
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:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

Try to start Eth0 device


# ifup eth0

Device eth0 does not seem to be present, delaying initialisation

To Solve this :

Delete networking interface rules file so that it can be regenerated and reboot your CentOS system.

Mã:
# rm /etc/udev/rules.d/70-persistent-net.rules
# reboot

New Mac address has been generated:

Mã:
# 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 0x8086:0x100e (e1000)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="08:00:27:fe:c1:03", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
Now edit /etc/sysconfig/network-scripts/ifcfg-eth0,

Add new HWADDR generated or remove it
Remove UUID line


Restart the networking service

# service network restart
Shutting down interface eth0: [ OK ]
Shutting down loopback interface: [ OK ]
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: Determining if ip address 192.168.1.99 is already in use for device eth0...
[ OK ]


# ifconfig
eth0 Link encap:Ethernet HWaddr 08:00:27:FE:C1:03
inet addr:192.168.1.99 Bcast:xxxxxxxx Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fefe:c103/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4400 errors:0 dropped:0 overruns:0 frame:0
TX packets:129 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:387597 (378.5 KiB) TX bytes:19567 (19.1 KiB)