:: MArX'' Frustrated communist, card-carrying geek.

GNS: OSPF Multi Area

A lot of people did like the early project: GNS: Routing redistribution example, so I decied to do another project, this one about OSPF Multi Area, subject suggested by a user at Linked In. Just like the previous project this subject is very important for those whishing todo the 642-901 (BSCI) test. A better understanding about stub areas, not so stub areas and virtual links are the main point of this project.

This is the scenary:

• Area 0: R1 and R2 (Area backbone)
• Area 1: R2 and R3 (Area configured as virtual link)
• Area 2: R3 and R4 (Area connected to ISP and nssa)
• Area 3: R1 and R5 (Area totally stub)

The lab is fully functional, 4 blocks /24 (192.168.0.0/22) where added to loopbacks in the Area 1 and another 4 in the Area 2 (192.168.4.0/22) for summarization routing tests purposes. Follow below some notes that could be useful:

1. Virtual Link is always configured between ABR routers in the area that will be utilized as transit.
2. Areas with Virtual Link can not be stub or not so stub.
3. NSSA areas do propagate summary routes and default route.
4. Totally stub areas just receive default routes.

You can download and enjoy the project here: GNS3 LAB - OSPF Multi Area . If you have any question, please let me know, send me a message!

By the way, I've used the Cisco IOS: c2600-i-mz.123-22.bin

I hope you liked it!