This is the second OSPF post I’ll be doing for CCIE lab preparation. Today I’m posting the tasks, then tomorrow or the day after (or possibly after the weekend, depending how busy I am) I’ll post the walkthrough. If any of you work on this before the walkthrough, leave a comment.

Here’s the topology:

(Click image for fullsize)

Click here for the initial configs

Here are the tasks:
1. Configure R1, R2 and R3′s S0/0 interfaces in Area 0. Ensure that DR and BDR are elected. Advertise all loopback0s on all routers into OSPF.

2. Configure R1 as the default gateway for all OSPF routers. Do not use the “default-information” command.

3. Configure R6 to use the path through R4 to get to area 0 Do not use any interface level commands to accomplish this.

4. Configure R4 to filter any type 3, 4, 5 and 7 LSAs from entering area 45.

5. Resolve discontigous area issues.

6. R5 is using a low-speed, high cost serial link to connect to R4. Ensure that the link is only used when needed.

7. Filter all loopback0s from entering R2′s RIB. Use a distribute list.

8. Configure loopback IPs,, and on R1. Inject a summary for these networks into OSPF, ensure that R2 and R3 see this summary and no specific routes. Do not use any summarization commands under the OSPF process to accomplish this.

9. Configure area 67 to elect a DR and BDR.
(Some of this might change during the walkthrough)

Here’s the .net file:
The Dynagen/GNS3 .net file
(you will need to change the paths to make it work)


Colby Glass has been in IT since 2002. He is currently a Systems Engineer (presales) with a Cisco Gold partner and holds the CCNP R/S, CCNP DC, CCDP, CCIP, JNCIA-ER.

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