Dell PowerConnect M6220 Configuration Manual

Also see for PowerConnect M6220: Release notes Configuration guide Cli reference guide Configuration guide Release note

Contents

80 Routing ConfigurationRoute PreferencesYou can use route preference assignment to control how the router chooses which routes to use whenalternatives exist. This section describes three uses of route preference assignment:• "Assigning Administrative Preferences to Routing Protocols" on page 80• "exit" on page 81• "Using Equal Cost Multipath" on page 81Assigning Administrative Preferences to Routing ProtocolsThe router may learn routes from various sources: static configuration, local route discovery, RIP, andOSPF. Most routing protocols use a route metric to determine the shortest path known to the protocol;however, these metrics are independent of one another and not easily comparable. Therefore, when therouter learns a route to a particular destination from two different sources, the metrics do not provide ameans of choosing the best route for your network.The PowerConnect 6200 Series switch enables you to identify the preferred route type by assigning anadministrative preference value to each type. The values are arbitrary (1 to 255); however, a route typethat has a lower value is preferred over higher-value types.Local routes are assigned an administrative preference value of 0 and are always preferred over otherroute types to local hosts. Static routes have a default value of 1; however, this value and all other defaultpreference values are user-configurable.A protocol can be assigned a preference value of 255 to prevent the router from forwarding packets usingthat protocol.Example 1: Configure Administrative PreferencesThe following commands configure the administrative preference for the RIP and OSPF:console#Configrouter ripdistance rip 130exitFor OSPF, an additional parameter identifies the type of OSPF route that the preference value applies to:router ospfdistance ospf ?inter Enter preference type inter.intra Enter preference type intra.type1 Enter preference type type1.type2 Enter preference type type2.distance ospf inter 170exit