Understanding the network.pdf - Back to Home

Now, here is the qualifier: Not every network needs to use a dynamic
routing protocol. There are pros and cons, and as a network
administrator, you need to make this decision. The rest of this chapter
provides you with the information you need in order to make it.
Routing Metrics
Routing metrics are used by dynamic routing protocols to establish
preferences for a particular route. All dynamic routing protocols use
some form of route metrics. In certain cases, a protocol can use only
one metric. Other protocols can use a collection of metrics, or a set of
metric parameters may be calculated together to establish a single,
but adjustable, metric. The goal of route metrics is to provide the
capability for the routing protocol to support the following network
attributes:
• Route diversity
• Route redundancy
• Load balancing
Route diversity exists when two or more unrelated access points or
paths exist for the same network. Route redundancy exists when two
or more access points to the same network exist with equal metrics.
Load balancing is the practice of distributing network traffic evenly
across multiple links. In Figure 8.3, all three of these elements are
possible.