Summary Route Drill 3

Like the other summary route drills, this post lists three practice problems. Each problem lists a set of subnet/mask pair for existing routes in some router. Your job: choose the subnet/mask pair to use as the best summary route that includes the addresses in all the routes in the original list. Here are some other useful links as well:

• All the Summary Route Drills in this blog
• Link to the ICND1 book, where you can learn more
• The post that explains the process to find the answers

Imagine that each column of Table 1 lists subnet/mask combinations that exist as routes in some router’s IP routing table. Your job: find the subnet/mask combination that you would configure in a manual summary route to replace all those routes with one summary route. Choose the best summary – that is, the summary route that includes all addresses in all the subordinate subnets, while including as few extra addresses as is possible.

Table 1 – Three Problems: Find the Best Summary Route for Each