2. Configure ISO Addressing

Purpose

For a router to support IS-IS, you must configure an ISO network entity title (NET) address on one of the router's interfaces, preferably the loopback interface (lo0).

Action

To configure ISO addressing, follow these steps:

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

[edit]

user@host# edit interfaces

2. Include a NET address for the loopback interface:

[edit interfaces]

user@host# set lo0 unit number family iso address address

3. Verify and commit the configuration:

user@host# show

user@host# commit 

Sample Output

user@R1> edit

Entering configuration mode

edit]

user@R1# edit interfaces

[edit interfaces]

user@R1# set lo0 unit 0 family iso address 49.0004.1000.0000.0001.00

[edit interfaces]

userR1# show 

[...Output truncated...]

lo0 {

    unit 0 {

        family inet {

            address 10.0.0.1/32;

        }

        family iso {

            address 49.0004.1000.0000.0001.00;

        }

    }

}

[edit interfaces]

user@R1# commit 

commit complete

What It Means

The sample output shows that the loopback (lo0) interface is configured with the NET address 49.0004.1000.0000.0001.00. The loopback interface (lo0) becomes a point of connection from the router to the IS-IS network. Every router in an IS-IS network must have at least one ISO NET address that identifies a point of connection to the IS-IS network. The NET address is generally configured on the loopback (lo0) interface. Routers that participate in multiple areas can have multiple NET addresses.

All the routers in the network shown in Figure 1 share a Level 2 database containing identical information. A common Level 2 database occurs in this case because all adjacencies are Level 2, and all routers are within the same IS-IS area (49.0004). Level 2 LSP flooding reaches all routers in the network due to the presence of a single level. For more information on determining the NET address, see the JUNOS Routing Protocols Configuration Guide.