3com 3.01.01 Manuale Utente

Integrated IS-IS is designed to function as a routing protocol for IP. Therefore, the 
network must be set up with IP addresses and VLANs in the same way that is 
required for RIP or OSPF. This set up is not discussed in this section. 

Beyond the standard IP setup, you must decide what type of routing hierarchy to 
implement. For example, should all routers be set up as level-2 or level-1 routers or 
should a level- 2 backbone be constructed connecting various level-1 areas? 

Regardless of your decision, the following configuration tasks are required for IS-IS 
to function as a routing protocol:

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Enabling IS-IS globally

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Setting up the desired VLANs and IP interfaces

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Setting the network entity title

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Enabling IS-IS on the required interfaces

Beyond these required commands, the following configuration tasks are common:

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Setting the router type and level, and the interface level based on the routing 
hierarchy you select

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Setting the cost of an interface to optimize routing decisions

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Setting authentication at the interface, area, or domain level using simple 
password or MD5 authentication

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Setting default route generation 

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Importing routes from, or exporting routes to, other protocols. To export to a 
protocol, see the section that discusses that protocol.

All of these commands are discussed in this section. This section also describes 
other commands that are used less frequently. For example, most users should not 
change the default values of the various protocol timers, nor do they need to 
change the SPF calculation parameters. Other commands described may be used 
under specific network conditions (large number of routes, highly meshed designs) 
to either optimize or troubleshoot IS-IS.

IS-IS configuration tasks are discussed in the following sections: 

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