Configure the Loopback Interface

On the router, you can configure one physical loopback interface, lo0, and you can configure one or more addresses on the interface. To do this, include the following statements at the [edit interfaces] hierarchy level:

 [edit]
 lo0 {
 	 unit 0 {
 	 	 family inet {
 	 	 	 loopback-address;
 	 	 	 <loopback-address2>;
 	 	 	 ...
 	 	 }
 	 }
 }
 

When specifying the loopback address, do not include a destination prefix.

In the following example, you configure two addresses on the loopback interface:

 [edit]
 user@host# edit interface lo0 unit 0 family inet
 [edit interface lo0 unit 0 family inet]
 user@host# set address 127.0.0.1 
 [edit interface lo0 unit 0 family inet]
 user@host# set address 10.0.0.1 
 [edit interface lo0 unit 0 family inet]
 user@host# top
 [edit]
 user@host# show
 interfaces {
 	 lo0 {
 	 	 unit 0 {
 	 	 	 family inet {
 	 	 	 	 127.0.0.1;
 	 	 	 	 10.0.0.1;
 	 	 	 }
 	 	 }
 	 }
 }