Transcript ROUTE10S03L10.ppt

Lab 3-4 Debrief
Implementing a Scalable Multiarea Network OSPFBased Solution
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Lab Topology
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Lab Review: What Did You Accomplish?
 Task 1: Examining OSPF Routing Information
– How can you verify the operation of an OSPF routing protocol?
– What you can see by observing OSPF neighbors, the OSPF
database, OSPF interfaces, and the IP routing table?
 Task 2: Optimizing OSPF Routing for Area 24
– What steps are required to restrict OSPF from announcing
information about OSPF external routers, while preserving the
insertion of internal routes from other areas?
 Task 3: Minimizing OSPF Information in Area 24
– What steps are also required to restrict OSPF from announcing
information about OSPF internal routers from other OSPF
areas?
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Lab Review: What Did You Accomplish?
(Cont.)
 Task 4: Reducing OSPF Information in Area 3
– What steps are required to minimize the sizes of the OSPF
link-state database and IP routing table on a router inside the
area in such a way that only information about the area
announced routes (internal or external) is allowed and
redistribution of external routes is preserved.
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Verification
 Did you have enough information to create an implementation
plan?
 Were you able to define the OSPF topology and content of the IP
routing table?
 After task 2, were external routes from other areas are
suppressed and internal routes, while internal routes remained in
the IP routing table and were injectable?
 After task 3, were external and internal routes from other areas
suppressed?
 After task 4, were external and internal routes from other areas
prevented from being injected, while redistribution of external
routes was allowed?
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Checkpoints
 Examine the IP routing information exchanged by routers
configured with the OSPF routing protocol.
 Change the area type to suppress external routes from other
areas to be injected.
 Check the IP routing table and OSPF database for verification.
 Change the area type to suppress external and internal routes
from other areas to be injected.
 Check the IP routing table and OSPF database for verification.
 Change the area type to suppress external and internal routes but
allow the injection of external routes into the area.
 Check the IP routing table and OSPF database for verification.
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A Sample Solution
 The IP routing table is verified for OSPF routes.
 The existing configuration of the area type for area 24 has been
changed from normal to stub and then to totally-stubby in order to
manipulate the insertion of routes into the area.
 The existing configuration for area 3 has been changed to a totally
not-so-stubby (NSSA) area in order to manipulate the insertion of
routes into the area.
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Alternative Solutions
 Summarization and filtering can be used in order to manipulate
the insertion of routes into a specific area.
 Because changing the routing protocol is not a realistic solution,
you can implement static and default routes with filtering instead.
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Q and A
 How you can verify OSPF routes and the OSPF topology?
 What can you change in OSPF to manipulate which routes are
inserted into an area?
 Which OSPF area type suppresses external routes from other
areas to be inserted?
 Which OSPF area type suppresses external and internal routes
from other areas to be inserted?
 Which area type suppresses external routes from other areas to
be inserted, but allows redistribution of external routes?
 Which area type suppresses external and internal routes from
other areas to be inserted, but allows redistribution of external
routes?
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Summary
 The IP routing table provides information that can be used to
verify the proper configuration of different OSPF area types.
 To optimize OSPF you must configure area 24 as an OSPF stub
area.
 To minimize OSPF information in area 24, you must configure an
OSPF totally-stub area.
 To reduce OSPF information in area 3, you must configure an
OSPF totally not-so-stubby (NSSA) area.
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