If you clone or move a Linux virtual machine created on a VMWare product the network adaptor will just disappear with no explanation. The usual solution is to delete the “xx-persistent-net.rules” file for Linux hosts, which makes the network adapter reaper after rebooting the system. However, I had a virtual machine with two network adapters (eth0, eth1) and only one of them worked (eth0). After digging for information I discovered that the interface configuration file only had one entry for eth0 and none for eth1. The solution was an easy one, just add the configuration for eth1. Note: the virtual machines was Ubuntu Server.
Open the interface configuration file.
And add the remaining network interface configuration.
# The secondary network interface
iface eth1 inet dhcp
Save and restart the system or networking service. Now issue the ifconfig command to see all available interfaces.