Access Control Lists (ACLs) | 121Use these commands to create route map instances. There is no limit to the number of set and matchcommands per route map, but the convention is to keep the number of match and set filters in a route maplow. Set commands do not require a corresponding match command.Configure a route map for route redistributionRoute maps on their own cannot affect traffic and must be included in different commands to affect routingtraffic. To apply a route map to traffic on the E-Series, you must call or include that route map in acommand such as the redistribute or default-information originate commands in OSPF, ISIS, and BGP.Route redistribution occurs when FTOS learns the advertising routes from static or directly connectedroutes or another routing protocol. Different protocols assign different values to redistributed routes toidentify either the routes and their origins. The metric value is the most common attribute that is changedto properly redistribute other routes into a routing protocol. Other attributes that can be changed includethe metric type (for example, external and internal route types in OSPF) and route tag. Use the redistributecommand in OSPF, RIP, ISIS, and BGP to set some of these attributes for routes that are redistributed intothose protocols.Route maps add to that redistribution capability by allowing you to match specific routes and set or changemore attributes when redistributing those routes.In Figure 6-25, the redistribute command calls the route map static ospf to redistribute only certain staticroutes into OSPF. According to the route map static ospf, only routes that have a next hop ofGigabitethernet interface 0/0 and that have a metric of 255 will be redistributed into the OSPF backbonearea.Figure 6-25. Route Redistribution into OSPFset origin {egp | igp | incomplete} CONFIG-ROUTE-MAP Assign an ORIGIN attribute.set tag tag-value CONFIG-ROUTE-MAP Specify a tag for the redistributed routes.set weight value CONFIG-ROUTE-MAP Specify a value as the route’s weight.Note: When re-distributing routes using route-maps, the user must take care to create the route-mapdefined in the redistribute command under the routing protocol. If no route-map is created, then NO routesare redistributed.Command Syntax Command Mode Purposerouter ospf 34default-information originate metric-type 1redistribute static metric 20 metric-type 2 tag 0 route-map staticospf!route-map staticospf permit 10match interface GigabitEthernet 0/0match metric 255set level backbone
