Options
Subnetting question
bcall64
Member Posts: 156
in CCNA & CCENT
Ok I'm solid with subnetting but I'm not under 30 seconds like everyone believes I should be.
I get questions where I have to figure out the host range for a subnetwork that is in the 200's or 100's and it takes some time.
For instance I need to find what network 192.168.200.141 /28 is on. Well easy enough I know my increment is 16 because my lowest bit is 16.
Now I am going to count up 192.168.200.0, 16, 32, 48, etc etc etc.
Well that's great and all but if I add these in my head I mistakes and get the question wrong. So I'm rushing through adding these numbers up and I get the answers right but it takes time. Anyone run into this same situation before?
Is there a trick to speed this up?
I get questions where I have to figure out the host range for a subnetwork that is in the 200's or 100's and it takes some time.
For instance I need to find what network 192.168.200.141 /28 is on. Well easy enough I know my increment is 16 because my lowest bit is 16.
Now I am going to count up 192.168.200.0, 16, 32, 48, etc etc etc.
Well that's great and all but if I add these in my head I mistakes and get the question wrong. So I'm rushing through adding these numbers up and I get the answers right but it takes time. Anyone run into this same situation before?
Is there a trick to speed this up?
Comments
-
Optionshexem Member Posts: 177Yeh, learn to count in 16's !
fowards and backwards, that way you don't have to start from 0 and count up, you can just look at the number and pick out where you should be.
I had trouble at first, but just kept going through it everyday. learn how many bit's are turned on/off for each mask, the slash notation's and everything. Reptition repetition repetition. say it out loud everyday.ICND1 - Passed 25/01/10
ICND2 - Passed 9/03/10
Studying CCNA:S -
Optionsbcall64 Member Posts: 156That's what I thought. Ok I have until Monday until my ICND1 exam.
Now before the exam you have about 10 minutes right in the room with a piece of paper or something? How does that work? Maybe I could write all of them out? -
Optionsmikem2te Member Posts: 407That's what I thought. Ok I have until Monday until my ICND1 exam.
Now before the exam you have about 10 minutes right in the room with a piece of paper or something? How does that work? Maybe I could write all of them out?8 7 6 5 4 3 2 1 128 64 32 16 8 4 2 1 128 192 224 240 248 252 254 255 255 127 61 31 15 7 3 1
It helps me to remember the possible subnet masks, wildcard masks and helps with identifiing the network in these types of questions.Blog : http://www.caerffili.co.uk/
Previous : Passed Configuring Microsoft Office SharePoint Server 2007 (70-630)
Currently : EIGRP & OSPF
Next : CCNP Route -
Optionsmiller811 Member Posts: 897Ok I'm solid with subnetting but I'm not under 30 seconds like everyone believes I should be.
I get questions where I have to figure out the host range for a subnetwork that is in the 200's or 100's and it takes some time.
For instance I need to find what network 192.168.200.141 /28 is on. Well easy enough I know my increment is 16 because my lowest bit is 16.
Now I am going to count up 192.168.200.0, 16, 32, 48, etc etc etc.
Well that's great and all but if I add these in my head I mistakes and get the question wrong. So I'm rushing through adding these numbers up and I get the answers right but it takes time. Anyone run into this same situation before?
Is there a trick to speed this up?
read this
http://www.techexams.net/forums/ccna-ccent/38772-subnetting-made-easy.html
then practice this
IP Subnet Practice
the more you do, the quicker it will become and the easier it will getI don't claim to be an expert, but I sure would like to become one someday.
Quest for 11K pages read in 2011
Page Count total to date - 1283 -
Optionsdaveccna Member Posts: 34 ■■□□□□□□□□Ok I'm solid with subnetting but I'm not under 30 seconds like everyone believes I should be.
I get questions where I have to figure out the host range for a subnetwork that is in the 200's or 100's and it takes some time.
For instance I need to find what network 192.168.200.141 /28 is on. Well easy enough I know my increment is 16 because my lowest bit is 16.
Now I am going to count up 192.168.200.0, 16, 32, 48, etc etc etc.
Well that's great and all but if I add these in my head I mistakes and get the question wrong. So I'm rushing through adding these numbers up and I get the answers right but it takes time. Anyone run into this same situation before?
Is there a trick to speed this up?
It may well have been on here that I read it but there is a quick way of answering the which subnet is this on question if you have the block size.
Simply divide the presented number by the block size and then cut any fraction off of the result. Then multiply your new whole number by the block size to get the network address.
Are you allowed a calculator in the exam?Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.
-Sun Tzu- -
Optionsmiller811 Member Posts: 897It may well have been on here that I read it but there is a quick way of answering the which subnet is this on question if you have the block size.
Simply divide the presented number by the block size and then cut any fraction off of the result. Then multiply your new whole number by the block size to get the network address.
Are you allowed a calculator in the exam?
No calculators.... sorryI don't claim to be an expert, but I sure would like to become one someday.
Quest for 11K pages read in 2011
Page Count total to date - 1283 -
Optionsdaveccna Member Posts: 34 ■■□□□□□□□□No calculators.... sorry
Well that being the case I tend to just break down an unmanagable multiplication in to chunks. Maybe do it in 2 steps.
EDIT or use a pencilVictorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.
-Sun Tzu- -
Optionsjohnwest43 Member Posts: 294If you can get it done in under a minute you shold be fine. There isnt a great need to do it in under 30 seconds like the book says.CCNP: ROUTE B][COLOR=#ff0000]x[/COLOR][/B , SWITCH B][COLOR=#ff0000]x[/COLOR][/B, TSHOOT [X ] Completed on 2/18/2014
-
Optionsthenjduke Member Posts: 894 ■■■■□□□□□□I wrote it all down on the board I got. I asked for three of them. Trust me 16 s a good number to learnCCNA, MCP, MCSA, MCSE, MCDST, MCITP Enterprise Administrator, Working towards Networking BS. CCNP is Next.
-
Optionsbcall64 Member Posts: 156I just want to thank everyone here for all the help. I laid in bed last night and added by 16's until I fell asleep. It wasn't that hard to get down! As for the chart that looks very very helpful. I will do that as well. I have been practicing subnetting A LOT and this weekend will be full of it. I feel like I should be able to pass this exam on Monday. Wish me luck!
-
Optionsblackninja Member Posts: 385This is what I do:
We are looking for network of 192.168.0.125 /28
= 192.168.0.125 255.255.255.255.240
Remember you don't have to count in 16s you can count muliples of 16.
We all know 4 x 16 = 64
then 2 x 64 = 128
128 - 16 = 112
So subnet of 192.168.0.125 /28 =
192.168.0.112 /28
It's that easyCurrently studying:
CCIE R&S - using INE workbooks & videos
Currently reading:
Everything. Twice -
Optionsbcall64 Member Posts: 156blackninja wrote: »This is what I do:
We are looking for network of 192.168.0.125 /28
= 192.168.0.125 255.255.255.255.240
Remember you don't have to count in 16s you can count muliples of 16.
We all know 4 x 16 = 64
then 2 x 64 = 128
128 - 16 = 112
So subnet of 192.168.0.125 /28 =
192.168.0.112 /28
It's that easy
Now that really makes things easier