I need to create local loopback as shown herein: Performing Loopback Testing for Fast Ethernet and Gigabit Ethernet Interfaces.ExcerptConfigure a Local Loopback ActionTo configure a local loopback without physically connecting the  transmit port to the receive port, follow these steps:In configuration mode, go to the following hierarchy level:[edit]user@host# edit interfaces interface-name (fastether-options |  gigether-options)Configure the local loopback:[edit interfaces interface-name (fastether-options | gigether-options)]user@host# set loopback
How can I create Local Loopback on Linux?
networking;ethernet
Here is their documentation on interface creation, titled: Red Hat Enterprise Linux 3: Reference Guide - Chapter 8. Network Interfaces.Add this line if it does not exist to /etc/hosts127.0.0.1       localhost       localhost.localdomainrun the following commands as root# ifconfig lo 127.0.0.1# route add 127.0.0.1Test the interface# ifconfig lolo    Link encap:Local Loopback      inet addr:127.0.0.1  Mask:255.0.0.0      UP LOOPBACK RUNNING  MTU:3924  Metric:1      RX packets:60 errors:0 dropped:0 overruns:0 frame:0      TX packets:60 errors:0 dropped:0 overruns:0 carrier:0      collisions:0 txqueuelen:0# ping localhostPING localhost (127.0.0.1): 56 data bytes64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=0.3 ms64 bytes from 127.0.0.1: icmp_seq=1 ttl=255 time=0.2 ms64 bytes from 127.0.0.1: icmp_seq=2 ttl=255 time=0.1 ms64 bytes from 127.0.0.1: icmp_seq=3 ttl=255 time=0.1 ms64 bytes from 127.0.0.1: icmp_seq=4 ttl=255 time=0.2 ms64 bytes from 127.0.0.1: icmp_seq=5 ttl=255 time=0.1 ms--- localhost ping statistics ---6 packets transmitted, 6 packets received, 0% packet lossround-trip min/avg/max = 0.1/0.1/0.3 ms