Trying to understand the question

jetdynamics

The Headquater has given IP address
range 192.168.0.0/27 for the network
behind our router, then you have to:
3.1 enable interface Fa0/0 and set
IP address/Subnet Mask to be the
last IP of this subnet that has
10 host as members.
3.2 enable interface Fa0/1 and set
IP address/Subnet Mask to be the
last IP of this subnet that has
5 host as members.
3.3 Set IP address/Subnet Mark of Host1
in each LAN to be the first IP of its
own subnet, and set IP of gateway also

What do you think is the answer and why ? For 3.1 , 3.2 and 3.3 , I am trying to figure out but would like to know your opinion. I will post the answer here once I see the explanation. I am getting confused how this question is worded.

martell1000

i would go like that:

192.168.0.0/27 is our subnet means we have 192.168.0.0 - 192.168.0.31 in our pool

first interface shall be last usable ip in a subnet with 10 clients in it, which gives us a /28 with a maximum useable addresses of 14,
range is 192.168.0.0 - 192.168.0.15, last usable address is 192.168.0.14 with a subnet mask of 255.255.255.240

second interface will be in a /29 with a maximum usable of 6 addresses of 6
range is 192.168.0.16 - 192.168.0.23, last usable address is 192.168.0.22 with a subnet mask of 255.255.255.248

host 1 in subnet 1: ip 192.168.0.1 gateway 192.168.0.14 (the routers interface) mask 255.255.255.240
host 1 in subnet 2: ip 192.168.0.17 gateway 192.168.0.22 (the routers interface) mask 255.255.255.248

Roguetadhg

The Headquater has given IP address
range 192.168.0.0/27 for the network
behind our router, then you have to:

3.1 enable interface Fa0/0 and set
IP address/Subnet Mask to be the
last IP of this subnet that has
10 host as members.

R1(config)#int fa0/0
R1(config-if)#ip address 192.168.0.14 255.255.255.240
R1(config-if)#no shut

- Subnet 192.168.0.0 255.255.255.224 - find the "subnet zero" that's made to accomdate 10 hosts. Ie: 255.255.255.240.

3.2 enable interface Fa0/1 and set
IP address/Subnet Mask to be the
last IP of this subnet that has
5 host as members.
- Find the next minimum subnet that have 5 valid host IP address. ie: 255.255.255.248

R1(config)#int fa0/1
R1(config-if)#ip address 192.168.0.22 255.255.255.248
R1(config-if)#no shut

Using VLSM and knowing that the SM is x.x.x.248 - the first subnet (x.x.x.240) takes up the first two possible ranges that could be used.
1) .0-.7
2) .8-.15
The third range would need to be used in this case. As it's the next minimal subnet range.
3) .16-.23

And my freaking Left speaker just died... I've sacrified my music for you all that read this thread. I'm now music-less.

3.3 Set IP address/Subnet Mark of Host1
in each LAN to be the first IP of its
own subnet, and set IP of gateway also
-- For each host:
1. IP Address: 192.168.0.1
Default Gateway: 192.168.0.14
Subnet Mask: 255.255.255.240
2. IP Address: 192.168.0.17
Default Gateway: 192.168.0.22
Subnet Mask: 255.255.255.248

What do you think is the answer and why ? For 3.1 , 3.2 and 3.3 , I am trying to figure out but would like to know your opinion. I will post the answer here once I see the explanation. I am getting confused how this question is worded.

jetdynamics

Thank you guys for the answer great explanation and correct answer!! How fast did you solve this type of question ? Any advice so I can time myself to solve it fast because on the exam time is very important.

ChickenNuggetz

jetdynamics wrote: »

Thank you guys for the answer great explanation and correct answer!! How fast did you solve this type of question ? Any advice so I can time myself to solve it fast because on the exam time is very important.

Practice Subnet Skills: Design a VLSM Network

This is what I use to practice VLSM.

martell1000

jetdynamics wrote: »

Thank you guys for the answer great explanation and correct answer!! How fast did you solve this type of question ? Any advice so I can time myself to solve it fast because on the exam time is very important.

this one took me less than 5 minutes , including writing the answer, which is more or less how i solved it in my head.
additionally, i visualized a network diagram in my mind to get a picture on how this would look like.
everyone has to find "his way" how to do subnetting.
when you found a way that works for you subnetting will become as easy as breathing.

(dont worry - last year that time it would have taken me 15 minutes to solve a task like that)

Roguetadhg

How do people get fast? Practice. A lot of practicing.

After a while of doing it, it just happens like running. But you need to be able to walk first.

By walking, I mean getting the problems right. Knowing that If borrow 4 bits from a /24 it'll be /28 subnet which means a "x.x.x.240" subnet. The X's I use to signify "Bits that can never change"

Don't try to force it. Just do problems on paper, write out the steps, doing the steps on paper will reinforce it in your head. Do 5 problems before you study, the more you do, the faster you'll master subnetting. It's really the only way.


Here are stuff I point to for subnetting lessons. Things that may or may not help you:

Use the calculators to check your work. Don't ****.


Shortcuts:
1. Subtracting wierd numbers.
An easier way of doing odd subtracting is by doing a smaller adding or subtracting first. Keeping a mental note, and then adding it or subtracting it from the final number.
Example: 91 - 64.
Step 1: Reduce/Increase the second number into a whole number: 64 (-4 = 60) or (+6 = 70). I'll subtract 4 to make 64 = 60.
Step 2: Subtract the new number: 91 - 60 = 31.
Step 3: Subtract the 4 from 31: 31 - 4 = 27.

Fun fact: It's called "Sutra".

2. Adding Binary
Look at the binary table: [ 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 ].
Can you see the groupings of numbers that make easy numbers when adding?

Let me show you:
[ 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 ]
Every other number creates a number that works with the number 5.
16 + 4 = 20, 128 + 32 = 170,...



How to subnet:
There's as many way to teach subnetting as there are stars in the sky. These, are just a sample:
Tech Exams: IPv4 Subnetting TechNotes
Learn to Subnet: Learn To Subnet:* A Free, Lecture-Based Presentation on IP Addressing and Subnetting
Microsoft: Chapter 4 - Subnetting
TechRepublic: IP subnetting made easy | TechRepublic
Cisco: IP Addressing and Subnetting for New Users - Cisco Systems
Tech Exams's Subnetting Test = Practice Exams - Subnetting Test (CCNA) - TechExams.net

Perfect Practice makes Perfect:
Random Network, Broadcast, First, Last Addresses and Ranges = subnettingquestions.com - Free Subnetting Questions and Answers Randomly Generated Online
VLSM Practice = Practice Subnet Skills: Design a VLSM Network

Select the class of networks: = Classes of Networks
Network, Broadcast and First,Last Usables = IP Subnet Practice
CIDR Mask to Dotted Decimal = CIDR to Dotted Decimal
Dotted Decimal to CIDR Mask = Dotted Decimal to CIDR


Subnet Calculators:
Ip Subnet Calculator: Online IP Subnet Calculator
Web Tools: IP Subnet Mask Calculator :: Webmaster Tools
VLSM: VLSM CIDR Subnet Calculator

lantech

jetdynamics wrote: »

Thank you guys for the answer great explanation and correct answer!! How fast did you solve this type of question ? Any advice so I can time myself to solve it fast because on the exam time is very important.

Practice by helping others to understand subnetting. Teaching others helps you to get better at a concept and helps you to better understand it.

Plus it's just good karma