Avaya 580 사용자 설명서

User Guide for the Avaya P580 and P882 Multiservice Switches, v6.1

15-1

The following information and procedures provided in this chapter pertain 
to layer 3 module configuration only:

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For more information about the CLI commands that are mentioned in this 
chapter, see Command Reference Guide for the Avaya P580 and P882 
Multiservice Switches, Software Version 6.1

OSPF (Open Shortest Path First) is a link state networking protocol. Each 
router broadcasts a packet that describes it own local links. Routers collect 
information from these broadcast packets to build their own network 
routing tables. These packets that describe the local links are short and 
cause less traffic congestion than Routing Information Protocol (RIP), 
which broadcasts large routing tables. 

OSPF bases its routing decision on the least-cost path. The cost is 
administered value, usually based on line speed. If there are multiple areas 
in an OSPF domain, there must be a backbone area, identified as area 0. 
When areas are configure in the OSPF domain, there are four basic router 
classifications:

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Internal Router — router with all directly connected networks 
belonging to the same area. Routers with only interfaces in the 
backbone area also belong to this category and have a single link-
state database.

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Area Border Router (ABR) — router that has directly connected 
networks belonging to multiple areas. ABRs have multiple link-
state databases, one for each area, including the backbone. ABRs