3com 3031 Instruccion De Instalación

Intermediate System-to-Intermediate System intra-domain routing information 
exchange protocol (IS-IS) is the dynamic routing protocol initially issued by the 
International Organization for Standardization (ISO) for its CLNP (ConnectionLess 
Network Protocol). To provide route support to IP, IETF extended IS-IS in RFC1195, 
nominating it as Integrated IS-IS or Dual IS-IS, which applies to TCP/IP and OSI 
environment simultaneously.

IS-IS protocol, based on the link state algorithm, uses the Shortest Path First (SPF) 
algorithm and highly resembles the Open Shortest Path First (OSPF) protocol. IS-IS, 
used for internal AS routing, is an Interior Gateway Protocol (IGP).

■

Intermediate System (IS). In ISO definitions, an Intermediate System (IS) is the 
equivalent of a router in the TCP/IP protocol suite. It is the basic unit in IS-IS 
protocol used for propagating routing information and generating routes. All 
references to "IS" and "router"will infer the same meaning as mentioned 
above.

■

End System (ES). In ISO definitions, an End System (ES) is the equivalent of a 
host in the TCP/IP protocol suite. ES does not involve in IS-IS processing. ISO has 
defined the ES-IS protocol as the communication protocol between the End 
Station and the Intermediate Station. This is analogous to ARP in the TCP/IP 
protocol suite

■

Routing Domain (RD). A group of ISs exchange routing information via the 
same routing protocol in a routing domain.

■

Area. An area is a subdivision of a routing domain.

■

Link State DataBase (LSDB). All the link states in the network form the LSDB. In 
an IS, at least one LSDB is available. The IS uses the SPF algorithm and the LSDB 
to generate its own routes.

■

Link State Protocol Data Unit (LSP). In the IS-IS, each IS will generate an LSP 
which contains all the link state information of the IS. Each IS collects all the 
LSPs in the local area to generate its own LSDB.

■

Network Protocol Data Unit (NPDU). It is the network layer packets of ISO and 
is equivalent to the IP packet in the TCP/IP suite.

■

DIS (Designated IS), an election router on a broadcast network.

■

NSAP (Network Service Access Point), namely a network layer address in the 
ISO system. It identifies an abstract network service access point and describes 
the network address for ISO model routing.