Alcatel-Lucent 6850 Switch User Manual


 
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide December 2007 page 3-1
3 Configuring IS-IS
Intermediate System-to-Intermediate System (IS-IS) is an International Organization for Standardization
(ISO) dynamic routing specification.
IS-IS is a shortest path first (SPF), or link state protocol. It is an interior gateway protocol (IGP) that
distributes routing information between routers in a single Autonomous System (AS) in IP as well as in
OSI environments. IS-IS chooses the least-cost path as the best path. IS-IS is suitable for complex
networks with large number of routers since it provides faster convergence where multiple flows to a
single destination can be forwarded through one or more interfaces simultaneously.
IS-IS is also an ISO Connectionless Network Protocol (CLNP). It communicates with its peers using the
Connectionless Mode Network Service (CLNS) PDU packets, which means that even in an IP-only envi-
ronment the IS-IS router must have an ISO address. ISO network-layer addressing is done through
Network Service Access Point (NSAP) addresses that identify any system in the OSI network.
Note. IS-IS is supported only on OmniSwitch 6850 and 9000 Series switches in Release 6.3.1.
In This Chapter
This chapter describes the basic components of IS-IS and how to configure them through the Command
Line Interface (CLI). CLI commands are used in the configuration examples; for more details about the
syntax of commands, refer the OmniSwitch CLI Reference Guide.
The configuration procedures described in this chapter include:
Loading and enabling IS-IS (see page 3-15).
Creating IS-IS areas (see page 3-16).
Creating IS-IS interfaces (see page 3-16).
Enabling IS-IS authentication (see page 3-18).
Creating redistribution policies using route maps (see page 3-24).
For information on creating and managing VLANs, see “Configuring VLANs” in the OmniSwitch 6800/
6850/9000 Network Configuration Guide.