Configuring a Network Entity Title (NET)

A NET is a Network Service Access Point (NSAP) address of varying length where the last byte (the NSAP-selector) is always zero. All intermediate systems within an IS-IS domain must use the same length NET. The first variable number of bytes identify the area, followed by seven fixed bytes that are divided between six bytes identifying the system ID and a single selector byte. Each intermediate system has a unique system identifier. To configure separate areas for the intermediate system, enter each area number, followed by the unique system ID for this intermediate system, followed by 00 (the NSAP-selector octet). For example: NET address 12.3333.4444.5555.6666.00 has an

• Area of 12.3333
• System identifier of 4444.5555.6666
• NSAP-selector of 00

The IS-IS process does not start until at least one NET is configured.

In IS-IS NET Configuration, three areas are defined: 47.0001, 47.0002, and 47.0003. Each intermediate system can belong to up to three areas. Router A is a Level 1-2 intermediate system with adjacencies in all three areas. Router B is a Level 1-2 intermediate system with adjacencies in areas 47.0001 and 47.0002. Router C is a Level 2 intermediate system with adjacencies only in area 47.0003.

Router A is configured for:

NET 47.0001.1000.5000.0001.00

NET 47.0002.1000.5000.0001.00

NET 47.0003.1000.5000.0001.00

The Level 1 adjacencies to Router A are configured with area 47.0001 and unique system IDs.

The following example configures the NETs for Router A:

S Chassis(rw)->configure
S Chassis(rw-config)->router isis
S Chassis(rw-config-isis)->net 47.0001.1000.5000.0001.00
S Chassis(rw-config-isis)->net 47.0002.1000.5000.0001.00
S Chassis(rw-config-isis)->net 47.0003.1000.5000.0001.00
S Chassis(rw-config-isis)->

Router B is configured for:

NET 47.0001.2000.5000.0001.00

NET 47.0002.2000.5000.0001.00

The Level 1 adjacencies to Router B are configured with area 47.0002 and unique system IDs.

The following example configures the NETs for Router B:

S Chassis(rw)->configure
S Chassis(rw-config)->router isis
S Chassis(rw-config-isis)->net 47.0001.2000.5000.0001.00
S Chassis(rw-config-isis)->net 47.0002.2000.5000.0001.00
S Chassis(rw-config-isis)->

Router C is configured for:

NET 47.0003.3000.5000.0001.00

Router A participates in a single-area domain. The area is area 47.0001 and the intermediate system identifier is 1000.5000.0001.

The following example configures the NETs for Router C:

S Chassis(rw)->configure
S Chassis(rw-config)->router isis
S Chassis(rw-config-isis)->net 47.0003.3000.5000.0001.00
S Chassis(rw-config-isis)->