Free first
- The textbook's companion site. The authors keep resources for the book at gaia.cs.umass.edu, including interactive problems you can repeat with new numbers.
- Your course's own syllabus. It tells you which chapters and which edition your exams use. Check it before you buy.
The textbook
Computer Networking: A Top-Down Approach, 9th edition
It starts with the applications you use (the web, email, DNS) and works down through transport, network and link layers. That order is why many courses pick it. If your course uses the 8th edition, a used copy of the 8th is usually the cheaper and safer choice, because section numbers differ between editions.
See the 9th edition on AmazonKestrel Exams earns a commission if you buy through this link. It costs you nothing extra and does not change what we recommend.
Practise for free
Kestrel's networking practice app and networking guides cover chapters 1 to 5 of the top-down sequence, with every number worked through. Free, with no ads and no account.