© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-1 Implementing a Scalable Multiarea Network OSPF- Based Solution Lab 3-1 Debrief

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-2 Lab Topology

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-3 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-to- point 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?

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-4 Lab Review: What Did You Accomplish? (Cont.)  Task 3: Configure OSPF over Frame Relay using the point-to- multipoint 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.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-5 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?

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-6 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?

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-7 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.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-8 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.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-9 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.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-10 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?

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-11 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.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—3-12