Como posso criar um Loopback Local no Linux?

Question

Eu preciso criar loopback local como mostrado aqui: Realizando o teste de loopback para interfaces Ethernet Fast Ethernet e Gigabit .

Trecho

Configure a Local Loopback Action

To configure a local loopback without physically connecting the transmit port to the receive port, follow these steps:

1. In configuration mode, go to the following hierarchy level:

   [edit]

   user@host# edit interfaces interface-name (fastether-options | gigether-options)

2. Configure the local loopback:

   [edit interfaces interface-name (fastether-options | gigether-options)]

   user@host# set loopback

    

Answer 1

Aqui está sua documentação sobre criação de interface, intitulada: Red Hat Enterprise Linux 3: Guia de Referência - Capítulo 8. Interfaces de Rede .

1. Adicione esta linha, se ela não existir para /etc/hosts

   127.0.0.1       localhost       localhost.localdomain
   

2. execute os seguintes comandos como root

   # ifconfig lo 127.0.0.1
   
   # route add 127.0.0.1
   

3. Teste a interface

   # ifconfig lo
   lo    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 localhost
   PING localhost (127.0.0.1): 56 data bytes
   64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=0.3 ms
   64 bytes from 127.0.0.1: icmp_seq=1 ttl=255 time=0.2 ms
   64 bytes from 127.0.0.1: icmp_seq=2 ttl=255 time=0.1 ms
   64 bytes from 127.0.0.1: icmp_seq=3 ttl=255 time=0.1 ms
   64 bytes from 127.0.0.1: icmp_seq=4 ttl=255 time=0.2 ms
   64 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 loss
   round-trip min/avg/max = 0.1/0.1/0.3 ms