Explain the role of interface lo, the loopback interface. In the output of netstat –in, what are the values of RX-OK (packets received) and TX-OK (packets transmitted) different for interface eth0 but identical for interface lo?

What will be an ideal response?

The loopback interface, lo, is a virtual interface which is generally assigned the IP address
127.0.0.1. If a host sends a packet to the loopback interface, the packet is immediately returned to the
network layer of the host. The loop-back interface is generally used for internal testing of the server, network operations etc. Since the packets are always returned back to itself the number of transmitted packets equals the number of received ones on lo. In case of eth0, it can have a packet dropped due to network errors which causes packet loss making the number of received packets different from the transmitted packets.