Lab 3-1 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: Configure OSPF over LAN interfaces
– What steps did you take to configure the OSPF routing
protocol and advertise all of the specific IP subnets used in the
network?
– How can you change the configuration to prevent any network
added to the router from being advertised?
– How does this change the default OSPF DR and BDR
selection on the LAN segment?
 Task 2: Configure OSPF over Frame Relay using the point-topoint OSPF network type
– What must you change on router R3 to be able to add a WAN
segment to the OSPF in the same area as the LAN segment?
– What must you change on router R4 to be able to add a WAN
segment to the OSPF in the same area as the LAN segment
and where only the WAN segment subnet is advertised?
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Lab Review: What Did You Accomplish?
(Cont.)
 Task 3: Configure OSPF over Frame Relay using the point-tomultipoint OSPF network type
– How does the configuration reflect the Frame Relay multipoint
network type when you include the WAN segment on router R1
into OSPF and enable OSPF adjacency over the serial
interface towards routers R2 and R4?
– How do you change the configuration to also advertise, from
the major network, any networks that are added later? This is
the OSPF configuration on routers R2 and R4, where the WAN
segment towards router R1 is included in the OSPF.
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Verification
 Did you have enough information to create an implementation
plan?
 Are the proper adjacencies established on the LAN segment?
 For how long are the adjacencies up?
 Do you see the proper OSPF routes in the IP routing table when
comparing it to the OSPF database?
 Which router is the DR on the LAN segment between routers R1
and R3?
 Are the proper adjacencies established on the WAN segment
between routers R3 and R4?
 For how long are the adjacencies up?
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Verification (Cont.)
 After enabling OSPF on the WAN segment, do you see the proper
OSPF routes in the IP routing table when comparing it to the
OSPF database?
 Are proper adjacencies established on the WAN segment
between routers R1, R2, and R4 in your pod?
 For how long are the adjacencies up?
 After enabling OSPF on the WAN segment on routers R2 and R4,
do you see the proper the OSPF routes in the IP routing table
when comparing it to the OSPF database?
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Checkpoints
 Configure the OSPF routing protocol on LAN segment.
 Advertise only the specific subnets used in the network.
 Check for the DR on the LAN segment.
 Configure the OSPF routing protocol on the WAN segment
between routers R3 and R4.
 Advertise only the specific subnets used in the network.
 Check for the correct OSPF network type on the WAN segments.
 Configure the OSPF routing protocol on the WAN segments
between routers R1, R2, and R4.
 Check for the proper entries in the IP routing table.
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Sample Solution
 Configure OSPF on the LAN segment and advertise only the
specific subnets used in the network.
 Configure OSPF on the WAN segment between routers R3 and
R4, and advertise only the specific subnets used in the network.
 Configure the OSPF routing protocol on the WAN segments
between routers R1, R2, and R4.
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Alternative Solutions
 You can use several routing protocols to provide reachability in
the network. Changing the routing protocol is not a realistic
solution, though you can modify the existing solution. You can
also fulfill the same requirements by reconfiguring to different
Frame Relay types.
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Q and A
 Why is routing protocol selection important?
 How is a DR and BDR selection performed?
 How is OSPF enabled on a LAN segment?
 Is an OSPF network type important when enabling an OSPF on
the WAN segment?
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Summary
 Configure OSPF on the LAN segment to advertise only specific
subnets and to observe DR selection.
 Configure OSPF on the WAN segment to advertise only specific
subnets.
 Configure OSPF on the WAN segment to advertise any additional
networks from the major network, if added later.
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