VLSM Practice Questions...

mattiplermattipler Member Posts: 175
Can anyone point me in the direction of a good source of variable length subnet mask questions... I've had a look on the t'internet and have only found the odd one or two questions dotted about the place. I understand the concepts completely and just need to polish off applying VLSM's quickly and accurately before I put in for the 801 in a few weeks.

Cheers guys.

Matt icon_wink.gif
Matt of England

Comments

  • NetstudentNetstudent Member Posts: 1,693 ■■■□□□□□□□
    Maybe you could just make up your own. Like pick some random numbers for the amount of hosts you would need in each subnet.

    Then use VLSM to contigously allocate the addresses. I haven't seen very many practice questions online that required you to do that.

    Like 522, 265, 300, 44, 69, 17, 2,2,2.

    Lets say you are given 172.31.0.0 /16 There you go, there is a practice VLSM question.
    There is no place like 127.0.0.1 BUT 209.62.5.3 is my 127.0.0.1 away from 127.0.0.1!
  • mattiplermattipler Member Posts: 175
    I had considered doing that but i'm 100% confident in my ability to do it correctly so would be useful to have a some kind of exam engine.
    Matt of England
  • NetstudentNetstudent Member Posts: 1,693 ■■■□□□□□□□
    I understand...Well hope you find something.
    There is no place like 127.0.0.1 BUT 209.62.5.3 is my 127.0.0.1 away from 127.0.0.1!
  • mattiplermattipler Member Posts: 175
    cheers m8 icon_wink.gif
    Matt of England
  • ehndeehnde Member Posts: 1,103
    Sorry to revive an old thread, but I'm wondering the same thing as the OP now....

    I know about subnettingquestions.com - Free Subnetting Questions and Answers Randomly Generated Online and subnetting.org - Free Subnetting Questions and Answers Randomly Generated Online but what about VLSM? It's been over 3 years since this thread was started. Maybe in the mean time someone has created such a site?
    Climb a mountain, tell no one.
  • johnwest43johnwest43 Member Posts: 294
    subnetting.org does have vlsm questions.
    CCNP: ROUTE B][COLOR=#ff0000]x[/COLOR][/B , SWITCH B][COLOR=#ff0000]x[/COLOR][/B, TSHOOT [X ] Completed on 2/18/2014
  • mella060mella060 Member Posts: 196
    Theres a few on this site...

    Cisco 5 Exercises
  • ehndeehnde Member Posts: 1,103
    johnwest43 wrote: »
    subnetting.org does have vlsm questions.

    I haven't seen any there. There are plenty of questions like this:
    Question: Your company needs to subnet their network to allow for 27 subnets while having as many host addresses available as possible. What subnet mask would you use on the 172.23.0.0 network to accomplish this?

    But nothing with VARIABLE length subnets that I've seen so far. Do you just keep answering questions and eventually see one? Or is there a subsection of the site?
    Climb a mountain, tell no one.
  • miller811miller811 Member Posts: 897
    what specifically are you having difficulties with?

    Here is an example from a previous post
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    The IP scheme that they gave you was a single subnet with 254 host possible.

    The example requested
    Network A 28 hours
    Network B 28 hosts
    Network C 14 hosts
    Network D 7 hosts
    Network E 2 hosts


    You need to then break it up into smaller subnets by subnetting......

    204.15.5.0 /24
    could be broken into two segments of 128 bits by changing the mask to a /25 = 126 usable hosts per subnet
    204.15.5.0 /25 204.15.5.0 - 204.15.5.127
    204.15.5.128/25 204.15.128-204.15.5.255

    it could also be broken into 4 subnets by starting out with a /26 mask = 62 usable host/subnet
    204.15.5.0 /26 204.15.5.0-204.15.5.63
    204.15.5.64/26 204.15.5.64-204.15.5.127
    204.15.5.128/26 204.15.5.128 - 204.15.5.191
    204.15.5.192/27 204.15.5.192-204.15.5.255

    it could also be broken into 8 subnets with a /27 mask = 30 usable hosts/subnet
    204.15.5.0 /27
    204.15.5.32/27
    204.15.5.64/27
    204.15.5.96/27
    204.15.5.128/27
    204.15.5.160/27
    204.15.5.192/27
    204.15.5.224/27

    it could also be broken into 16 subnets with a /28 mask = 14 usable hosts
    it could also be broken into 32 subnets with a /29 mask = 6 usable hosts
    it could also be broken into 64 subnets with a /30 mask = 2 usable hosts

    So you take the highest number of host you need per subnet first, 2 of the networks required 28 hosts, so the first 2 subnets would be /27

    204.15.5.0 /27
    204.15.5.32/27

    since the second subnet extends to 204.15.5.63, the starting point for the next subnet would be 204.15.5.64

    The next subnet requires 14 hosts, we would use a /28 mask

    so 204.15.5.64 /28 = 204.15.5.64-204.15.5-79

    the next subnet requires 7 hosts, so we would need to use a /28 mask again
    so we would start with the next IP
    204.15.5.80 /28 = 204.15.5.80 - 204.15.5.95

    the last subnet only requires 2 IP address so we would use a /30 mask
    the next IP address is
    204.15.5.96 /30 = 204.15.5.96 - 204.15.5.99

    Hope that helps
    I don't claim to be an expert, but I sure would like to become one someday.

    Quest for 11K pages read in 2011
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  • PristonPriston Member Posts: 999 ■■■■□□□□□□
    I'm more interested in ip version 6 vlsm. icon_wink.gif
    A.A.S. in Networking Technologies
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  • ehndeehnde Member Posts: 1,103
    Not having difficulty, I just appreciate the luxury of random practice questions on sites like subnetting.org. Maybe we should build a VLSM question generator site? haha :D
    Climb a mountain, tell no one.
  • Excellent1Excellent1 Member Posts: 461 ■■■■■■□□□□
    Sorry to necro an older thread, but I wanted to share a site I found to practice VLSM, both the implementation and summarization. It's not hard to make your own practice scenarios, but convenience is...convenient. I found this thread while googling for practice examples, so I thought I'd share it here. If this is posted elsewhere, my apologies.

    Practice Subnet Skills: Design a VLSM Network
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