Home > ICND1 – Subnetting 2

ICND1 – Subnetting 2

June 15th, 2017 in ICND1 100-105 Go to comments

Note: If you are not sure about Subnetting, please read my Subnetting Made Easy tutorial.

Question 1


AREA 1 has 500 users but it uses class C which only supports 254 users (from to> A is correct.

AREA 3 also uses class C and as mentioned above it supports 254 users so it is enough for 200 users -> B is incorrect.

In AREA 2 there are only 60 users < 64 = 26 so we can use a subnet mask which has 6 bits 0 -> /26. Of course we can use larger subnets (like /25) for future expansion -> C is correct.

A large network should never use a single network-wide mask. It should be some different subnet masks to make the network flexible and easy to be summarized -> D is incorrect.

For router-to-router connection we should use a subnet mask of /30 which supports 2 hosts per subnet. This subnet mask is ideal for router-to-router connection -> E is correct.

There is no limit for IP to function if we know how to organize our network -> F is incorrect.

Question 2


The maximum number of hosts in this question is 50 hosts so we have to use /26 subnet mask or above.

Question 3


To support 300 workstations in a single broadcast domain, we need to use a subnet mask which supports 512 hosts = 29 -> /23 or in decimal form -> A is correct.

If we use 48-port switches we need 300/48 = 6.25 -> seven 48-port switches are enough because we also need trunking between them -> D is correct.

We only need one router interface and it is connected with one of seven switches -> E is correct.

Question 4


/19 = The fast way to find out this subnet mask is to remember /16 = and we need 3 more bits 1 for 3rd octet: 1110 0000 which is 224.

Question 5

Question 6


Increment: 2 (/23 = 11111111.11111111.11111110.00000000 =
Network address: (because 2 = 2 * 1 and 2 < 3)
Broadcast address: (because 2 + 2 – 1 = 3 for the 3rd octet)

-> The lowest (first assignable) host address is and the broadcast address of the subnet is

Question 7

Explanation = 1111 1111.1111 1111.1111 1111.1110 0000 (binary form)

Increment: 32

First subnetwork: -> (A is incorrect because is a broadcast address)
Second subnetwork: ->
Third subnetwork: -> (B is incorrect because is a network address)
Fourth subnetwork: -> (C is incorrect because is a broadcast address)
Fifth subnetwork: ->
Sixth subnetwork: -> (D is correct because is the last assignable host address of this subnetwork)
Seventh subnetwork: -> (E is incorrect because is a network address)

Question 8

Question 9

Question 10

Question 11


The IP address of host B must be in the range of subnet, which ranges from to (Increment: 16), except the IP addresses of, (which are the network and broadcast addresses of the subnet),, (which have been assigned to the interface’s router and the switch). Therefore there are only two IP addresses of &

Question 12

Question 13

Question 14

Question 15


From the /28 we can find all information we need:

Increment: 16 (/28 = 11111111.11111111.11111111.11110000)
Network address: (because 16 < 23)
Broadcast address: (because 31 = 16 + 16 – 1)

In fact we don’t need to find out the broadcast address because the question only asks about subnet address (network address).

Comments (25) Comments
  1. CCENT Someday
    January 29th, 2014

    If you need help learning to subnet, etc. Here is a video that I used to refresh and/or learn from:


  2. CCENT Someday
    January 31st, 2014


    I plan on taking exam next week. What other sims/labs did you get besides the OSPF 6 router?

    Thanks in Advance!

  3. Qazi
    February 16th, 2014

    Question no.2, I think none of the answers are correct.
    since, its mentioned clearly that choosen IP is (which comes in Class B with a default mask of /16). More over the design scheme is supposed to be a Classful addressing.

    If you decide to go with /26 network then it will become a Classless Subnetting.
    Even though options are not valid. If those are valid please explain in detail.
    Im about to give exam very soon.

  4. Konan
    March 3rd, 2014

    @Qazi,clasfull in other word means that the address has 3parts,that include:network,subnet,host.In this case has 3parts as well.16bits network, 10bits subnet and 6bits host part.Classfull addressing doesnt mean that the mask is the default mask for IP.

  5. Reza
    April 1st, 2014

    In Q3, why do we need to any router? It hasn’t been requested to connect the network to anywhere, has it?

  6. Boner Jamz
    April 12th, 2014

    Hi Reza

    Cisco is a little funny with their wording. You need a router because this is the expansion of a new network onto the existing network. Thus you need a router to route the IP packets.

  7. fez
    April 24th, 2014

    Passed my 100-101 exam today and question 1,2,3,4 were there.. all the best

  8. Manohar Tn
    May 16th, 2014

    Got 986/1000 Marks, {5/16/2014} 50 Questions, Ospf Sim, Security simlet, and Router and switch Simlet Was also there…..All questions From 9tut. and Examcollections…..Now Heading For Icnd2 And Blogging…..

    For Any Help.
    Manohar Tn
    Website: http://www.techlinko.com
    G+ : https://plus.google.com/u/0/+ManoharTN9/

  9. tut
    June 8th, 2014

    guys check this link… Very good video on ip addressing and sub netting


  10. MO
    August 8th, 2014

    Are these questions included in the real ICD1 exam?

  11. Q
    August 21st, 2014

    Question 3 is correct. Pretty sure the subnet to be used has support for 510 hosts, not 512. The broadcast address and next network address makes it necessary to substract 2 from 512. Doesn’t affect the answer, just a technicality.

  12. Anonymous
    September 15th, 2014

    Hi,can someone Email me.lastest CertExam cant open Dumps.Email:emnico2002@yahoo.com

  13. Gabbie
    October 17th, 2014

    Hi, my exam is this Monday, please send me the latest icnd1 dumps , many thanks! gfedejko@yahoo.com

  14. Ahmed
    March 28th, 2015

    q1 in exam

  15. Ronny
    April 4th, 2015

    Hi Guys , just passed the ICND1 with 100% score, most questions are the same as 9tut. Thanks 9tut!! Question 1 & 3 were there!

  16. Anonymous
    April 15th, 2015

    Hi Guys , just passed the ICND1. most questions are the same as 9tut. Thanks 9tut!! Question 1, 3 & 4 were there!

  17. G-10
    April 26th, 2015

    Q 1, 4 in exam

  18. Anonymous
    July 5th, 2015


  19. 9tut
    July 13th, 2015

    @all: We had to move all the questions and answers out of 9tut. We can only keep the explanation. You can download the questions and answers at: https://mega.co.nz/#!oIdESYbD!yyu33vygrfKPy4rcmcbV6qW2fxINNoTokuDM3CjA_og

  20. Anonymous
    August 29th, 2015

    what happen to the question? no question only explanation?

  21. preety
    November 30th, 2015

    questions plzzz????

  22. Angie
    March 22nd, 2016

    Hi Guys i’m writing ICDN1 next week anyone how wrote this year already,to advise on who was the exam?

  23. shadows
    November 8th, 2016

    Guys, I cant see the Question. It says Question and there is no Question and an Explanation is given ???? Why is this ???

  24. networking by standard
    January 28th, 2017

    This is a very powerful prep website for CCNA exams. I thought I was prepared enough but getting here, I have seen soo many contributions of great minds in CCNA. Thank you all.

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