7.3 IGRP  
  7.3.1 IGRP features  
IGRP is a distance vector Interior Gateway Protocol (IGP). Distance vector routing protocols mathematically compare routes by measuring distances. This measurement is known as the distance vector. Routers using distance vector protocols must send all or a portion of their routing table in a routing update message at regular intervals to each of their neighboring routers. As routing information spreads throughout the network, routers perform the following functions:
  • Identify new destinations
  • Learn of failures

IGRP is a distance vector routing protocol developed by Cisco. IGRP sends routing updates at 90 second intervals, advertising networks for a particular autonomous system. Key design characteristics of IGRP are a follows:

  • The versatility to automatically handle indefinite, complex topologies
  • The flexibility needed to segment with different bandwidth and delay characteristics
  • Scalability for functioning in very large networks

By default, the IGRP routing protocol uses bandwidth and delay as metrics. Additionally, IGRP can be configured to use a combination of variables to determine a composite metric. Those variables include:

  • Bandwidth
  • Delay
  • Load
  • Reliability
 

Interactive Media Activity

Checkbox: RIP versus IGRP

After completing this activity, the student will be able to understand RIP and IGRP.

 
 

Web Links

Specifying a Next Hop IP Address for Static Routes

http://www.cisco.com/en/US/tech/tk826/ tk365/technologies_tech_ note09186a00800ef7b2.shtml