When you clone or ‘deploy from template’ a linux virtual machine on Vmware, specifically Red Hat based linux such as CentOS, you need additional steps on the cloned machine to make it work. The obvious settings you need to change are the IP address and hostname. But changing those settings is not enough. You also need to change other parameters.

When you clone a linux machine, the hardware address (or MAC address) of the NIC changes, which is correct — the cloned machine should never have the same MAC address as the source. However, the new MAC address is assigned to eth1, not eth0. The eth0 is still assigned the MAC address of the source, although it is commented out in udev’s network persistent file, so it’s not active.

When you cloned a linux machine and noticed that the network does not work, it is probably because you assigned the new IP address to eth0 (which is not active). You can use eth1 and assign the new IP address on that interface. However, I usually want to use eth0 to make it clean and simple. You can easily switch back to eth0 by editing the file /etc/udev/rules.d/70-persistent-net.rules. Edit the string that starts with SUBSYSTEM, remove or comment out the line for eth1, uncomment the line for eth0, and replace the ATTR(address) for eth0 to get the MAC address from eth1. Here’s a sample edited file:

# 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 0x8086:0x100f (e1000)
#SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:60:66:88:00:02",
ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

Now edit the /etc/sysconfig/network-scripts/ifcfg-eth0 file to make sure that the DEVICE is eth0, the BOOTPROTO is static, and the HWADDR matches the ATTR{address} for eth0 in the 70-persistent-net.rules file.

Restart the network by issuing the command “service network restart” or you can reboot the system.