ever confused with "discontinued networks" and "auto summary" command in Cisco routers?

If you read only Sybex's "CCNA study guide", which is so well known in the Cisco certification community, and you don't have too much experience, you most likely lost yourself. So this book is not that good as so many people say.

Refer to
http://www.oreilly.com/
catalog/iprouting/chapter/ch04.html#31695

for what is "discontinued networks"