Cisco IOS ISO CLNS Configuration Guide, Release 12.4T
ISO CLNS Overview
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ISO CLNS Overview

Table Of Contents

ISO CLNS Overview


ISO CLNS Overview

Cisco IOS software supports a variety of network protocols. The Cisco IOS ISO CLNS Configuration Guide discusses the following network protocol:


The Cisco IOS IP Configuration Guide discusses the following network protocols:


IP Routing

This overview chapter provides a high-level description of ISO CLNS. For configuration information, see the appropriate section in this publication.


Cisco IOS software supports packet forwarding and routing for ISO CLNS on networks using a variety of data link layers: Ethernet, Token Ring, FDDI, and serial.

You can use CLNS routing on serial interfaces with HDLC, PPP, Link Access Procedure, Balanced (LAPB), X.25, SMDS, or Frame Relay encapsulation. To use HDLC encapsulation, you must have a router at both ends of the link. If you use X.25 encapsulation, you must manually enter the network service access point (NSAP)-to-X.121 mapping. The LAPB, X.25, Frame Relay, and SMDS encapsulations interoperate with other vendors.

The Cisco CLNS implementation also is compliant with the Government OSI Profile (GOSIP) Version 2.

As part of its CLNS support, Cisco routers fully support the following ISO and American National Standards Institute (ANSI) standard:

ISO 9542—Documents the ES-IS routing exchange protocol.

ISO 8473—Documents the ISO Connectionless Network Protocol (CLNP).

ISO 8348/Ad2—Documents NSAP addresses.

ISO 10589—Documents IS-IS Intradomain Routing Exchange Protocol.

Both the ISO-developed IS-IS routing protocol and the Cisco ISO Interior Gateway Routing Protocol (IGRP) are supported for dynamic routing of ISO CLNS. In addition, static routing for ISO CLNS is supported.

Note Cisco access servers currently support ES-IS routing protocol and not IS-IS routing protocol.