unavailable, the routers on Beetlenet can take full advantage of an alternate path to a given
destination. In this example, the paths are derived using EIGRP. However, the paths could have
been derived statically or by using other dynamic protocols such as RIP, IGRP, and OSPF. If a
router on Beetlenet receives and installs multiple paths with the same administrative distance
and cost to a destination, load balancing will occur. The IGRP routing processes support
unequal-cost load balancing. In this scenario, the
destination (fast switching) or per packet (process switching) on Beetlenet. If it's done by
destination using the ip route-cache command on the serial interface, the router distributes the
packets based on the destination address. Per-packet load balancing or process switching is
configured with the
John over the second path.
is known as unequal-cost load balancing. Unequal-cost load balancing allows traffic to be
distributed among multiple (up to four) unequal-cost paths to provide greater overall throughput
and reliability. Alternative path variance (that is, the difference in desirability between the
primary and alternative paths) is used to determine the feasibility of a potential route. An
alternative route is feasible if the next router in the path is closer to the destination (has a lower
metric value) than the current router and if the metric for the entire alternative path is within the
variance. Only paths that are feasible can be used for load balancing and can be included in the