Configuring Iso Clns Routing; Configuring Iso Igrp Dynamic Routing - Cisco Catalyst 3750 Software Configuration Manual

Chapter 28 Configuring IP Unicast Routing

Configuring ISO CLNS Routing

The International Organization for Standardization (ISO) Connectionless Network Service (CLNS)
protocol is a standard for the network layer of the Open System Interconnection (OSI) model. Addresses
in the ISO network architecture are referred to as network service access point (NSAP) addresses and
network entity titles (NETs). Each node in an OSI network has one or more NETs. In addition, each node
has many NSAP addresses.
When you enable connectionless routing on the switch by using the clns routing global configuration
command, the switch makes only forwarding decisions, with no routing-related functionality. For
dynamic routing, you must also enable a routing protocol. The switch supports these dynamic routing
protocols for ISO CLNS networks:
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When dynamically routing, you can choose either ISO IGRP or IS-IS, or you can enable both routing
protocols at the same time. Both routing protocols support the concept of areas. Within an area, all
routers know how to reach all the system IDs. Between areas, routers know how to reach the proper area.
ISO IGRP supports three levels of routing: system routing, area routing, and interdomain routing.
Routing across domains (interdomain routing) can be done either statically or dynamically with ISO
IGRP. IS-IS supports two levels of routing: station routing (within an area) and area routing (between
areas).
The key difference between the ISO IGRP and IS-IS NSAP addressing schemes is in the definition of
area addresses. Both use the system ID for Level 1 routing (routing within an area). However, they differ
in the way addresses are specified for area routing. An ISO IGRP NSAP address includes three separate
fields for routing: the domain, area, and system ID. An IS-IS address includes two fields: a single
continuous area field (comprising the domain and area fields) and the system ID.
This section contains this ISO CLNS configuration information:
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Note For more detailed information about ISO CLNS, refer to the Cisco IOS Apollo Domain, Banyan VINES,
DECnet, ISO CLNS and XNS Configuration Guide for Release 12.1. For complete syntax and usage
information for the commands used in this chapter, refer to the Cisco IOS Apollo Domain, Banyan
VINES, DECnet, ISO CLNS and XNS Command Reference for Release 12.1, use the IOS command
reference master index, or search online.

Configuring ISO IGRP Dynamic Routing

The ISO IGRP is a dynamic distance-vector protocol designed by Cisco Systems for routing an
autonomous system that contains large, arbitrarily complex networks with diverse bandwidth and delay
characteristics. This section briefly describes how to configure ISO IGRP. It includes this information:
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78-15870-01
ISO Interior Gateway Routing Protocol (IGRP)
Intermediate System-to-Intermediate System (IS-IS) routing
Configuring ISO IGRP Dynamic Routing, page 28-63
Configuring IS-IS Dynamic Routing, page 28-66
Default ISO IGRP Configuration, page 28-64
Enabling ISO IGRP, page 28-64
Configuring Optional ISO IGRP Parameters, page 28-65
Catalyst 3750 Metro Switch Software Configuration Guide
Configuring ISO CLNS Routing
28-63