Configuring Routing Policies; Overview; Route Preferences - HP procurve 8100fl series Management And Configuration Manual

Configuring Routing Policies

Overview

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Overview

The 8100fl switch supports flexible routing policies. These allow the network
administrator to control import and export of routing information based on
criteria including:
■ Source and destination interface
Previous hop router
■
■ Tag associated with routes
■ Specific destination address
The network administrator can specify a preference level for each
combination of routing information being imported by using a flexible
masking capability.
The switch also provides the ability to create advanced and simple routing
policies. Simple routing policies provide a quick route redistribution between
various routing protocols (RIP and OSPF). Advanced routing policies provide
more control over route redistribution.

Route Preferences

Preference (or distance) is the value the switch routing process uses to order
preference of routes from one protocol or peer over another. Preference can
be set using several different configuration commands. You can set preference
based on one network interface over another, or from one remote gateway
over another. However, you cannot use preference to control the selection of
routes within an Interior Gateway Protocol (IGP). This is accomplished
automatically by the protocol based on metrics.
You can use preference to select routes from the same Exterior Gateway
Protocol (EGP) learned from different peers or autonomous systems. Each
route has only one preference value associated with it, even though the
preference can be set at many places using configuration commands. The last
or most specific preference value set for a route is the value used. A preference
value is an arbitrarily assigned value used to determine the order of routes to
the same destination in a single routing database. The active route is chosen
by the lowest preference value.