Multicast and Routing Guide K/KA/KB.15.15

Viewing the current IP load-sharing configuration.................................................................189
Overview of OSPF................................................................................................................189
OSPF router types............................................................................................................190
Interior routers.............................................................................................................190
Area border routers (ABRs)...........................................................................................191
Autonomous system boundary router (ASBR)...................................................................191
Designated routers (DRs)..............................................................................................191
OSPF area types..................................................................................................................193
Backbone area................................................................................................................193
Normal area...................................................................................................................194
Not-so-stubby-area (NSSA)................................................................................................194
Stub area........................................................................................................................194
OSPF RFC compliance..........................................................................................................195
Reducing AS external LSAs and Type-3 summary LSAs...............................................................195
Algorithm for AS external LSA reduction..............................................................................196
Replacing type-3summary LSAs and type-7 default external LSAs with a type-3 default route
LSA................................................................................................................................196
Equal cost multi-path routing (ECMP).......................................................................................196
Dynamic OSPF activation and configuration.............................................................................198
General configuration steps for OSPF.................................................................................199
Configuration rules......................................................................................................199
OSPF global and interface settings................................................................................200
Changing the RFC 1583 OSPF compliance setting....................................................................200
Assigning the routing switch to OSPF areas..............................................................................200
Configuring for external route redistribution in an OSPF domain.................................................201
Configuring ranges on an ABR to reduce advertising to the backbone.........................................201
Influencing route choices by changing the administrative distance default (optional)......................201
Adjusting performance by changing the VLAN or subnet interface settings...................................202
Configuring OSPF interface authentication...............................................................................202
Configuring an ABR to use a virtual link to the backbone...........................................................202
Adjusting virtual link performance by changing the interface settings...........................................203
Configuring OSPF authentication on a virtual link......................................................................203
About OSPF passive..............................................................................................................203
About configuring shortest path first (SPF) scheduling.................................................................203
Graceful shutdown of OSPF routing.........................................................................................203
Modules operating in nonstop mode..................................................................................204
OSPF equal-cost multipath (ECMP) for different subnets available through the same next-hop
routes.............................................................................................................................204
8 Route Policy...........................................................................................205
Using prefix lists...................................................................................................................205
Creating prefix list entries..................................................................................................205
Entering a prefix list description.........................................................................................206
Viewing prefix lists...........................................................................................................207
Creating a route map............................................................................................................208
Deleting all or part of a route map.....................................................................................208
Viewing route maps.........................................................................................................209
Using match commands........................................................................................................209
Matching VLANs.............................................................................................................209
Matching prefix lists.........................................................................................................209
Matching next-hop addresses............................................................................................209
Matching route sources.....................................................................................................210
Matching route metrics.....................................................................................................210
Matching metric types......................................................................................................210
Matching source protocols................................................................................................210
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