Subnetting Exercises

The following three problems are examples of common problems in the networking industry.  They get increasingly difficult.  If you can get through these without too much trouble, you’ll likely be fine for subnetting questions on the CCNA R&S 1 Final exam.

Within minutes of me posting these questions, I’m sure that you’ll be able to find solutions online.  Don’t.  Your best bet for learning this material is to work on these problems on your own, then compare your results against the results from someone else in your class.  Try to figure out why answers differ.  Once you’re pretty sure you have the correct answers, show them to your instructor (with your work, of course) for final verification.

Let me know if there is any desire for more subnet / supernet questions.  There are always more…


Problem #1

Given the host, what is the:
1) network address
2) subnet mask
3) broadcast address


Problem #2

A senior network admin from your parent company has assigned your office  In your office you have these VLANs:
a) HR and Legal – 20 workstations
b) Developers – 63 workstations
c) Help desk – 8 workstations
d) Servers – 60 servers
e) Printers – 4 printers

You have a single router in your office.  Create an IP address allocation plan.  Document gateway addresses, network addresses, netmasks, and broadcast addresses.  There is no external (Internet) connection.  Also document any unallocated network addresses.


Problem #3

The outgoing network admin at your company has left you with a messy list of networks that you need to advertise to your head office.  Summarize the networks the best way possible to ensure that your summaries do not include networks that could be in use elsewhere in the network.