Subnetting Made Easy, VLSM, Cisco® CCNA 640-801 Test Questions, Guaranteed pass

In today's environment it is important to use a summary address (route summarization) when working with IPv4 and large networks to conserve space in the routing tables and reduce CPU cycles in the router. The Cisco® 640-802 objectives (CCNA) expects us to understand not only summarization, but also to be able to identify subnet overlapping.

Our Subnetting Made Easy study guide was updated February 2, 2010 to reflect these needs. We have expanded and further simplified VLSM problem solving, manual route summarization, and expanded our Subnetting Made Easy to include subnet overlapping to meet the newer Cisco® CCNA objectives.

Overlapping subnets has never been simplier to identify and resolve than today, with our new study guide.
In our exhibit we would use a summary address to advertise a single route out the serial interface of the Wheresville router to the Whoesville router to the backbone.

But with this configuration is it possible? Can you readily identify why this network configuration will fail? Can you identify where subnet overlapping will cause intermittent or total failure of packet delivery? Tough question, and one that Cisco® would not have asked a few years ago, but they will ask today on the CCNA exam.

We need to be fairly comfortable with VLSM (Variable length subnet mask) on the Cisco® CCNA exam as well as the Microsoft® 70-291 (2003 environment) which is Network Mangement.