Subnetting Drills: Find the Subnet ID

certskills
By certskills March 8, 2011 11:40

Since this week’s question requires that you do some sub netting math, it seemed like a good time to toss out some sub netting practice questions. I plan to add a techie topic video about how to find these subnet IDs without using binary math, but in the mean time, here’s the practice. The focus is on finding the subnet ID, not so much what a subnet ID is and what it’s used for. Post queries if you have them!!

Find the subnet ID of the following:

10.4.77.99, 255.255.0.0

10.4.77.99, 255.255.255.0

172.30.201.199, 255.255.255.0

10.4.77.99, 255.255.240.0

10.4.77.99, 255.255.255.224

172.30.201.199, 255.255.255.248

192.168.1.199, 255.255.255.248

.

.

.

.

.

Hello world!
Answer to Monday's Subnetting Speed Test Question
certskills
By certskills March 8, 2011 11:40
Write a comment

10 Comments

  1. Max March 10, 00:44

    AS far as I have done this the subnet ID’s are as follows

    Questions Solution
    10.4.77.99, 255.255.0.0 – 10.4.0.0

    10.4.77.99, 255.255.255.0 – 10.4.77.0

    172.30.201.199, 255.255.255.0 – 172.30.201.0

    10.4.77.99, 255.255.240.0 – 10.4.64.0

    10.4.77.99, 255.255.255.224 – 10.4.77.96

    172.30.201.199, 255.255.255.248 – 172.30.201.192

    192.168.1.199, 255.255.255.248 – 192.168.1.192

    Reply to this comment
  2. certskills March 10, 06:03

    @Max –
    Thanks for the post. All are correct!
    @All –
    A rhetorical question – are you ready to get these answers within your time goal?
    And another subnet question – were any of these subnet broadcast addresses?
    Wendell

    Reply to this comment
  3. Dan February 3, 15:20

    10.4.77.99, 255.255.0.0
    10.4.0.0 10.4.0.1 – 10.4.255.254 Broadcast 10.4.255.255

    10.4.77.99, 255.255.255.0
    10.4.77.0 10.4.77.1 – 10.4.77.254 Broadcast 10.4.77.255

    172.30.201.199, 255.255.255.0
    172.30.201.0 172.30.201.1 – 172.30.201.254 Broadcast 172.30.201.255

    10.4.77.99, 255.255.240.0
    10.4.76.0 10.4.76.1 – 10.4.91.254 Broadcast 10.4.91.255

    10.4.77.99, 255.255.255.224
    10.4.77.64 10.4.77.65 – 10.4.77.94 Broadcast 10.4.77.95

    172.30.201.199, 255.255.255.248
    172.30.201.192 172.30.201.193 – 172.30.201.198 Broadcast 172.30.201.199

    192.168.1.199, 255.255.255.248
    192.168.1.192 192.168.1.193 – 192.168.1.198 Broadcast 192.168.1.199

    Reply to this comment
    • Wendell Odom of Certskills February 3, 15:52

      Hi Dan,
      I like them all, except the 4th one… I’m confident you’ll see the mistake once you re-look. Thanks for the post!
      Wendell

      Reply to this comment
      • Mirek May 27, 12:55

        I’m not confident about the 5th one either.
        Problem IP Address Mask Subnet ID Broadcast Adress First IP Last IP
        10.4.77.99, 255.255.0.0 10.4.0.0 10.4.255.255 10.4.0.1 10.4.255.254
        10.4.77.99, 255.255.255.0 10.4.77.0 10.4.77.255 10.4.77.1 10.4.77.254
        172.30.201.199, 255.255.255.0 172.30.201.0 172.30.201.255 172.30.201.1 172.30.201.254
        10.4.77.99, 255.255.240.0 10.4.64.0 10.4.79.255 10.4.64.1 10.4.79.254
        10.4.77.99, 255.255.255.224 10.4.77.96 10.4.77.127 10.4.77.97 10.4.77.126
        172.30.201.199, 255.255.255.248 172.30.201.192 172.30.201.199 172.30.201.193 172.30.201.198
        192.168.1.199, 255.255.255.248 192.168.1.192 192.168.1.199 192.168.1.193 192.168.1.198

        Reply to this comment
  4. Anna September 8, 10:06

    Hi Wendell,

    I watched different tutorials on subnetting, learned some bits and pieces but your book laid out all the rules which made me feel comfortable on this topic.

    Thanks,
    Anna

    Reply to this comment
  5. Bav June 21, 08:52

    I am now at the point where I can do them in my head in under 10 seconds. Is that good for the exam?

    Reply to this comment
View comments

Write a comment

Comment; Identify w/ Social Media or Email

Subscribe

Subscribe to our mailing list and get interesting stuff and updates to your email inbox.

Thank you for subscribing.

Something went wrong.

Search

Categories