Transcript ROUTE10S03L06

Lab 3-2 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: Configuring OSPF backbone area
– What steps did you take to configure the OSPF routing
protocol on a router belonging to the backbone area?
 Task 2: Configuring OSPF nonbackbone areas
– What steps did you take to configure the OSPF routing
protocol on routers belonging to different nonbackbone areas?
 Task 3: Tuning an OSPF operation
– How can the default cost calculation be changed?
– How can the router ID be changed?
– How can you preserve CPU cycles on router R3 by eliminating
the unnecessary OSPF traffic on a LAN segment?
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Verification
 Did you have enough information to create an implementation
plan?
 Is adjacency in area 0 between routers R1 and BBR2
established?
 Is the IP routing table populated with correct OSPF routes?
 Is adjacency established between the routers of nonbackbone
areas?
 Is the IP routing table populated with the correct OSPF routes?
 How is a change in cost calculation done?
 What is the router ID of router R1?
 Is the IP routing table populated with the correct OSPF routes?
 Did router R3 stop trying to set up an OSPF adjacency via the
LAN segment?
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Checkpoints
 Configure OSPF in area 0.
 Check for adjacencies in area 0 between routers R1 and BBR2.
 Check the IP routing table for the proper OSPF routes.
 Configure OSPF in nonbackbone areas
 Check if an adjacency is established between the routers of
nonbackbone areas.
 Check the IP routing table for proper OSPF routes.
 Change the cost calculation.
 Manipulate the OSPF router ID of router R1.
 Check the IP routing table for the proper OSPF routes.
 Check that router R3 stopped trying to set up an OSPF adjacency
via the LAN segment.
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Sample Solution
 Configure OSPF for backbone and nonbackbone areas.
 Select the correct OSPF network type for each WAN segment.
 Change the default cost calculation to manipulate the path
selection and change the router ID to manipulate DR and BDR
selection.
 Configure the passive interface to suppress routing traffic and
preserve CPU cycles on router R3.
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Alternative Solutions
 You can design different backbone and nonbackbone areas, for
which nonbackbone areas can be non-standard in order to reduce
the number of routing updates.
 You can configure a different IP adress on the loopback interface
to manipulate the router ID.
 Because changing the routing protocol is not a realistic solution,
you can configure static and default routes.
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Q and A
 What is the purpose of backbone and nonbackbone areas?
 How can a default cost calculation be changed?
 Why is the router ID important?
 How does a passive interface work in an OSPF routing protocol?
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Summary
 Configure OSPF for a backbone area.
 Configure OSPF for a nonbackbone area.
 Tune OSPF operation by changing how default cost calculation is
performed; you can change the cost calculation by changing the
router ID and configuring a passive interface. Doing this preserves
CPU cycles by eliminating unnecessary OSPF traffic on the LAN
segment.
© 2009 Cisco Systems, Inc. All rights reserved.
ROUTE v1.0—3-9
© 2009 Cisco Systems, Inc. All rights reserved.
ROUTE v1.0—3-10