NET

A network entity title (NET) identifies the network layer information of an IS. It does not include transport layer information. A NET is a special NSAP address with the SEL being 0. The length of a NET ranges from 8 bytes to 20 bytes, same as a NSAP address.

A NET includes the following parts:

• Area ID—Has a length of 1 to 13 bytes.

• System ID—A system ID uniquely identifies a host or router in the area and has a fixed length of 6 bytes.

• SEL—Has a value of 0 and a fixed length of 1 byte.

For example, for a NET ab.cdef.1234.5678.9abc.00, the area ID is ab.cdef, the system ID is 1234.5678.9abc, and the SEL is 00.

Typically, a router only needs one NET, but it can have a maximum of three NETs for smooth area merging and partitioning. When you configure multiple NETs, make sure the system IDs are the same.