|
Home > Archive > CCNA > June 2001 > subnetting
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
|
|
|
| Man, subnetting is sure complicated. I don't know how I'm ever going to learn how to do it. I know it is required for routing but man there has to be a easier way to learn it. On the surface (when you first start out) it seems pretty easy just simple math for the most part at first but in no time it gets like, "what?!" How much subnetting is done out there in the real world nowdays anybody know? Can you get by with this cert with just limited knowlege of it? I'm sure you need to have it masted to be a Cisco pro but man it sure seems tough, man... (shaking my head.) Oh well, back to the books. Just venting a little.
I hope it starts to sort of just come together soon, racking my brain about it and one day it's just like oh yeah I know how this works, kind of like how the OSI model just sort of made sense one day you know. | |
|
| Lots of subnetting is used in the outside world - sorry if that's not want you want to hear!
If your simply going to "monitor" a network and call somebody else out to do the work then you'll get by - but who want's to get by?
From what I remember there is 2 methods - the cisco one, with lots of 0's, 1's and and's, all really complicated if you don't already know binary. Or the Sybex method which is easy to remember if you count 0 to 9 like everybody I know(or at least I thought so) Which one are you using??
Eddycurrents made a great post as below -
http://www.examnotes.net/forums/sho...&threadid=18755
I learnt the Cisco way and was a bit old fashioned about learning the Sybex way, but once you get the hang of it you'll be subnetting in seconds - no problem.
Good luck. | |
|
| Yeah I have the SYBEX book by Lammle but I still need to pick the virtual lab kit. Oh I WILL learn this stuff and WILL pass this test, I'm just getting going on it it and bang! it got a little confusing that's all. Great link/post though printed that one out should come in handy. How long till they change this test though? | |
|
| Subnetting is easy if you look at it the right way. I teach it in 20minutes in all my MCSE classes.
Take a look at my site and you will see the study guide I created for my students. Oh,and it is free 
Let me know if I can help! | |
| liquidplatinum 2001-06-14, 7:22 pm |
| I was just about to recommend Freak's site to you before I read further and saw that he already did! I'm still going through it, but it sure is good. Thanks Freak! | |
|
| Subnetting can be a XXXXX to learn yes but keep at it and you will get it, it took me a long time to get on to it but when I did it was like gee this is simple how come it took me so long, I can now do it in my sleep ..
Keep at it you'll get it  | |
| studio78 2001-06-14, 8:22 pm |
| Face, use freak's guide to learn subnetting. I did and learned it with ease. It's very simple to understand because it's explained so well. My biggest fear with the CCNA exam was subnetting but freak's guide took care of that. I passed with a 946. Good luck.
quote:
Originally posted by freak
Subnetting is easy if you look at it the right way. I teach it in 20minutes in all my MCSE classes.
Take a look at my site and you will see the study guide I created for my students. Oh,and it is free
Let me know if I can help!
| |
| Yeti-GBR1 2001-06-14, 9:15 pm |
| Ok here's how I learnt Subnetting.
You have an IP Address of 198.187.15.56 and a subnet mask of /28 ( this is equivalent to 255.255.255.240 since you are using 4 bits from the last octet..i.e. 11111111.11111111.11111111.11110000 = 255.255.255.240)
Question:
What are the valid Subnets available to you and how many valid hosts are there per subnet?
Ok this is how you do it in only 4!!! lines.
Line 1. 256-240 = 16 which means there are subnets every 16 addresses, this gives 16,32,48,56,64...all the way to 240-16=224 since you cannot have all 1's or 0's in the addresses this eliminates 0 and 240.
Line 2. Number of valid hosts per subnet are 2^(host bits used = 4) - 2 = 2^4 - 2 = 16 - 2 = 14
Line 3. Number of valid Subnets for the IP Address are 2^(Network Bits used = 4) - 2 = 2^4 - 2 = 14
Line 4. Broadcast addresses of the subnets will be -1 from the next value, thus the broadcast address for 16 is 32-1 = 31. Do this for the rest now.
Thus in 4!!! lines you have the following information:
Assuming the 1st 3 octets are 198.187.15 then
Available Subnets are (last Octet value):
16,32,48,64,80,96,112,128,144,
160,176,192,208,224
Available hosts respectivley are:
Host Range Braodcast Address
1. 1-14 15
2. 17-30 31
3. 31-46 47
4. 49-62 63
5. 65-78 79
6. 81-94 95
7. 113-126 127
8. 129-142 143
9. 145-158 159
10. 161-174 145
11. 177-190 191
12. 193-206 207
13. 209-222 223
14. 225-238 239
Hope this helps.
This can also be used for Class A, B or C(as above) just takes slightly more brain power thats all.
BTW the IP Address 198.187.15.56 is in the subnet 198.187.15.48 since it lies between 49-62 | |
|
| Thanks for the information and encouragement guys, that is why this site is so useful. I have all kinds of resources to learn subnetting including a CBT I have for N+ that has a good section on subnetting with some cool graphics to help visualize the process so I shouldn't have a problem learning this. It sure is cool to just post a few thoughts on the subject though and have everybody just come out of the woodwork to offer advice and study tools to use that I didn't have before. Thanks again guys. | |
| RTRGOD 2001-06-16, 9:04 pm |
| I teach CCNA for a local school and subnetting is always the hardest part for my students to understand. I tell them not to get discouraged, and to keep practicing. One day, a light bulb will come on and you WILL be able to subnet in your head. No paper, no pen, no calculator, no cheat-sheets. Most of my students have come back months later and told me that I was right. They look back on it and laugh. When the light bulb goes on for you, it will be a happy day. Keep at it.
Also, if you want to pursue routing as a career, you MUST know how to subnet. If you want to pursue CCNP or CCIE you MUST know how to subnet, and do it quickly. You cannot afford to waste time on your tests dealing with subnetting problems. | |
|
| quote:
Originally posted by liquidplatinum
I was just about to recommend Freak's site to you before I read further and saw that he already did! I'm still going through it, but it sure is good. Thanks Freak!
You are very welcome! I am happy my site could be of help | |
|
| quote:
Originally posted by studio78
Face, use freak's guide to learn subnetting. I did and learned it with ease. It's very simple to understand because it's explained so well. My biggest fear with the CCNA exam was subnetting but freak's guide took care of that. I passed with a 946. Good luck.
Thanks, your kind words made my day I am happy I could be of help. I love this site and the opportunity it gives to help out and learn from your peers at the same time... | |
| vhmtai 2001-06-18, 8:32 pm |
| don't worry. Actually subnetting is not that difficult. let me introduce a book to you. The subnetting part in the CCNA book published by Sybex is quite good and I think it explains more clear than those in MCSE.  | |
| rlrouns 2001-06-19, 6:08 pm |
| I dont think that anyone has mentioned www.learntosubnet.com It is a great site, and explains subnetting in audio and slide format with windows media player. Also it has a some written exercises that you can do as well. I personally went through all of learntosubnet.com,then read and re-read the sybex book part about subnetting, and to really drill it in, you can type in subnetting tutorial in your search engine and see what you come up with. The 3com tutorial is really good, and Freaks site is as well. If you hit it from enough angles, you will get it. I think that the written drills helped me the most. I hope this helps!
Rob | |
| sauser 2001-06-20, 12:51 pm |
| yeah subnetting is an old friend of mine!!
it took me a week to get comfortable with it!
but now i look back at it and laugh |
|
|
|
|