* Discount code PD2019 confers a 35% discount off the list price of one, or a 55% discount off the list price of two or more eligible print books, eBooks, Web Editions, full-course video, software, and Practice Test titles purchased on ciscopress.com. Discount not valid on Book + eBook bundles, Book/eBook + Video bundles, individual video lessons, non-discountable products, Rough Cuts, Safari Books Online, or any title featured as eBook Deal of the Week or Video Deal of the Week. If any items are canceled or returned, and the order is no longer eligible for a volume-based discount code that was applied to the purchase, remaining items will be invoiced at the standard discounted price shown on the website. Discount code may not be combined with any other offer and is not redeemable for cash. Discount offer expires 11:59 p.m. EST February 25, 2019. Offer subject to change.