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324 Chapter 9: WAN Design Considerations
routing table. These conditions limit the number of cases in which load balancing can occur but
ensure that the dynamics of the network remain stable.
The following general rules apply to IGRP unequal-cost load balancing:
·
IGRP accepts up to four paths for a given destination network.
·
The local best metric must be greater than the metric learned from the next router. In other
words, the next-hop router must be closer (have a smaller metric value) to the destination
than the local best metric.
·
The alternative path metric must be within the specified variance of the local best metric.
The multiplier times the local best metric for the destination must be greater than or equal
to the metric through the next router.
87200333.book Page 324 Wednesday, August 22, 2001 2:53 PM