Avaya P3343T-ML 사용자 설명서

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Chapter 12        Avaya P330 Layer 3 Features
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Avaya P334T-ML User’s Guide
OSPF (Open Shortest Path First) Configuration
OSPF Overview
OSPF is a routing protocol developed for IP networks based on the shortest path 
first or link-state algorithm. It was introduced to overcome the limitations of RIP in 
increasingly complex network designs.
OSPF is based on the cost of a particular path. In contrast, RIP uses hops as a path 
criterion. Also, updates are sent on a “need to know” basis rather than every 30 
seconds as with RIP. 
The advantage of shortest path first algorithms is that they result in smaller more 
frequent updates everywhere. They converge quickly, thus preventing such 
problems as routing loops and Count-to-Infinity (when routers continuously 
increment the hop count to a particular network). This stabilizes the network. 
The disadvantage of shortest path first algorithms is that they require a lot of CPU 
power and memory. 
Routers use link-state algorithms to send routing information to all nodes in an 
internetwork by calculating the shortest path to each node. This calculation is based 
on a topography of the Internet constructed by each node. Each router sends that 
portion of the routing table (keeps track of routes to particular network 
destinations) that describes the state of its own links, and it also sends the complete 
routing structure (topography). 
The P330 supports the OSPF routing protocol. The P330 can serve as an OSPF 
Autonomous System Boundary Router (ASBR) by configuration of route 
redistribution. The P330 can be installed in the OSPF backbone area (area 0.0.0.0) or 
in any OSPF area that is part of a multiple areas network. However, the P330 cannot 
be configured to be an OSPF area border router itself. 
The P330 supports the equal-cost multipath (ECMP) feature which allows load 
balancing by splitting traffic between several equivalent paths.
While OSPF can be activated with default values for each interface using a single 
command, many of the OSPF parameters are configurable.
For a detailed description of OSPF, refer to the OSPF standards and published 
literature.