two days til CCENT

xnx

Deathmage wrote: »

I used subnetting.net like 7 months ago when I didn't know subnetting as well as I do now. I think I'll revisit it and add that to my daily madness..

Question for the CCNP's... does it get any easier with CCNP or is CCENT/CCNA supposed to be this hard with the Cisco Exams and how they word them? ...or is just a fact of life that I need to get used to their poor wording?

CCNP is much more difficult sadly, you've really got to be dedicated to learning the protocols and even reading RFCs when the books need calrification

Deathmage

xnx wrote: »

CCNP is much more difficult sadly, you've really got to be dedicated to learning the protocols and even reading RFCs when the books need calrification

Well just wondering if it better on the other end of the tunnel.

Deathmage

dam you Cisco and your hard exams. Would so love to apply for this but not until I vanquish this dragon with my blunt sword. Where is that flash drive with the "sword of a thousand truths"?

This place would be 10 minutes from the house.



Must study harder (if that's even possible), so many positions looking for CCNA Engineers in this area.

Deathmage

Well I've listened to you all from the likes of ninjaturtle, Mow, xnx, Blackout, Jon_Cisco, Dakinggamer87, Mooseboost, kMastaFlash, JoJoCAl19, and many others I may have not mentioned and I've read all of your PM's closely. Very humbled to have so much support.

In response to all your words of wisdom I've been completely re-reading Todd's book from scratch as if it was my 1st time, however it's now my 5th time reading it. Strangely enough even though I truly do think I know the basics of the book I'm reading it as if it was my 1st time. I'm still somehow absorbing thing to stick into my brain; I did take 3 days off this week doing not a single bit of networking - maybe my skull needed a break.. Maybe we all just need time to process things, dunno. Just wish it wasn't a $300 learning curve, lol.

Anyways, been living on Subnetting.net and I've been doing something new with my labs. I'm going through each section in the running-config and seeing what I can do to possibly break it and then fix it. I think today alone I spent most of the day making problems on my network like intentionally setting the hello and dead intervals to something other than the defaults of 10 and 40 respectfully to see what it did and other little thing like not enabling encapsulation on a serial link or flipping a DCE/DTE cable from a interface that was look for it that had a clock speed set to other thing like my NAT Overload pool name boo-boo if anyone remembers that learning scenario.

I'm making sure I really understand a setting or feature not just enough to get by with 'ya I know what it does', I'm diving deeper into it. One thing I've done thus far is take for granted small things but I'm treating them like learning to drive a car for the 1st time. I really don't want to fail a 3rd time, I seriously do feel I know this material so I'm royally pissed I failed and it only makes me want it more...nothing is being taken for granted including subnetting Class A's. I've gotten to a point now with my Adobe Acrobat 11 Pro I've made a interactive subnetting chart (probably could have done it in Excel but meh I'm an over-achiever) with each one of the three classes with empty bubbles for each section so I can make scenarios and not have to write it out each time; it lets me really sink in the CIDR's - a tad excessive, maybe, but I seriously HATE FAILING! ... going for the overkill approach.

Again thanks for everyone encouraging words, had no idea I had so many people following me.

thomas_

koz24 wrote: »

How would they hold it against you? Dude, just find the answer any way you can. If show run works and it gets you the answer then use it!

I agree with koz24, my thought process is that if they don't want you to use a "show running-config" on a simlet then you are not going to be able to use that command. If it's available use it, if it's not then work your way around it.

As far as subnetting goes, here's how I do it. If it helps you great, if it doesn't then just forget I even wrote it.

I don't use a magic number or anything like that. I just remember that when you have a set of 8 bits the left-most bit when turned on has a 128 decimal value, second from the left = 64, third from left =32, fourth from left = 16.

The above is important because that value will tell you how much you should increment each subnet by in a particular octet.

Let's assume a network had an original /8 address and we are going to subnet it. In a /9 subnet there is only one bit being used in the second octet for subnetting. Since a subnet mask by definition has only consecutive ones starting from the left(11111111.10000000.0.0) that means the subnets will increment by 128 within the second octet, we are doing nothing with the first octet since that originally contained all network bits. The two subnets are x.0.0.0 and x.128.0.0

If you had a /10 ip address the subnet mask would be (11111111.11000000.0.0). In this case two bits are being used in the second octet for subnetting. Looking at their respective decimal values, starting from the left they are 128 and 64 respectively. Based on this I know that the subnets are going to be multiples of 64 starting with 0. The subnets then are x.0.0.0, x.64.0.0, x.128.0.0, x.192.0.0.

If we looked at the subnet mask in decimal it would be 255.192.0.0. The magic number tells you to subtract 256-192 = 64. Notice how this is equal to the decimal value of the subnet bit being used that is the farthest to the right in the second octet.

If you had a /11 ip address the subnet mask would be (11111111.11100000.x.x). Now there are three bits in the second octet being used for subnetting. Looking at their decimal values from left to right they are 128, 64, and 32. We can conclude that the subnets are going to increments of 32 starting with 0. The subnets are x.0.0.0, x.32.0.0, x.64.0.0, x.96.0.0, x.128.0.0, x.160.0.0, x.192.0.0, x.224.0.0.

The decimal subnet mask for above is 255.224.0.0. Using the magic number 256-224 = 32. Again Notice how this number corresponds to the decimal value of the subnet bit that is furthest to the right when it is turned on.

If you have a subnetting problem that crosses octet boundaries that is where it gets a little tricky. Lets say that you are using a /9 for subnetting, but the original network only used /7 for the network. This would mean that in the first octet, the far right bit is the only one being used for subnetting. In the second octet the far left bit is the only bit being used for networking.(nnnnnnns.shhhhhhh.hhhhhhhh.hhhhhhhh) where n =network bits, s = subnet bits, h = host bits.

For the sake of discussion let's say the original network is 64.0.0.0 /7. The first seven bits are unchanging. Bits 8 and 9 are the bits that gives us our subnets. The new subnets would then be 64.0.0.0 /9(the subnet bit in the first and second octet are both turned off), 64.128.0.0 /9(subnet bit in first octet off, subnet bit in second octet on), 65.0.0.0 /9(subnet bit in first octet is on, second octet is off), and 65.128.0.0(subnet bit in both octets on).

If we analyze it we see that the second octet only changed by multiples of 128, but only when the subnet bit was on. The first octets value was only being changed by multiples of 1, but only for the cases when the subnet bit for the first octet was turned on. The broadcast address for the first subnet would be 64.127.255.255(one less than the second subnet id), for the second it would be 64.255.255.255(one less than the third subnet id), for the third it would be 65.127.255.255(one less than the fourth subnet id) and for the fourth it would be 65.255.255.255.

Once you know the ranges you just have to figure out which subnet range a given ip address falls within. Once you know which octets you are working within for the subnets it gets pretty easy to find the subnet the ip address is in.

Deathmage

thomas_ wrote: »

I agree with koz24, my thought process is that if they don't want you to use a "show running-config" on a simlet then you are not going to be able to use that command. If it's available use it, if it's not then work your way around it.

As far as subnetting goes, here's how I do it. If it helps you great, if it doesn't then just forget I even wrote it.

I don't use a magic number or anything like that. I just remember that when you have a set of 8 bits the left-most bit when turned on has a 128 decimal value, second from the left = 64, third from left =32, fourth from left = 16.

The above is important because that value will tell you how much you should increment each subnet by in a particular octet.

Let's assume a network had an original /8 address and we are going to subnet it. In a /9 subnet there is only one bit being used in the second octet for subnetting. Since a subnet mask by definition has only consecutive ones starting from the left(11111111.10000000.0.0) that means the subnets will increment by 128 within the second octet, we are doing nothing with the first octet since that originally contained all network bits. The two subnets are x.0.0.0 and x.128.0.0

If you had a /10 ip address the subnet mask would be (11111111.11000000.0.0). In this case two bits are being used in the second octet for subnetting. Looking at their respective decimal values, starting from the left they are 128 and 64 respectively. Based on this I know that the subnets are going to be multiples of 64 starting with 0. The subnets then are x.0.0.0, x.64.0.0, x.128.0.0, x.192.0.0.

If we looked at the subnet mask in decimal it would be 255.192.0.0. The magic number tells you to subtract 256-192 = 64. Notice how this is equal to the decimal value of the subnet bit being used that is the farthest to the right in the second octet.

If you had a /11 ip address the subnet mask would be (11111111.11100000.x.x). Now there are three bits in the second octet being used for subnetting. Looking at their decimal values from left to right they are 128, 64, and 32. We can conclude that the subnets are going to increments of 32 starting with 0. The subnets are x.0.0.0, x.32.0.0, x.64.0.0, x.96.0.0, x.128.0.0, x.160.0.0, x.192.0.0, x.224.0.0.

The decimal subnet mask for above is 255.224.0.0. Using the magic number 256-224 = 32. Again Notice how this number corresponds to the decimal value of the subnet bit that is furthest to the right when it is turned on.

If you have a subnetting problem that crosses octet boundaries that is where it gets a little tricky. Lets say that you are using a /9 for subnetting, but the original network only used /7 for the network. This would mean that in the first octet, the far right bit is the only one being used for subnetting. In the second octet the far left bit is the only bit being used for networking.(nnnnnnns.shhhhhhh.hhhhhhhh.hhhhhhhh) where n =network bits, s = subnet bits, h = host bits.

For the sake of discussion let's say the original network is 64.0.0.0 /7. The first seven bits are unchanging. Bits 8 and 9 are the bits that gives us our subnets. The new subnets would then be 64.0.0.0 /9(the subnet bit in the first and second octet are both turned off), 64.128.0.0 /9(subnet bit in first octet off, subnet bit in second octet on), 65.0.0.0 /9(subnet bit in first octet is on, second octet is off), and 65.128.0.0(subnet bit in both octets on).

If we analyze it we see that the second octet only changed by multiples of 128, but only when the subnet bit was on. The first octets value was only being changed by multiples of 1, but only for the cases when the subnet bit for the first octet was turned on. The broadcast address for the first subnet would be 64.127.255.255(one less than the second subnet id), for the second it would be 64.255.255.255(one less than the third subnet id), for the third it would be 65.127.255.255(one less than the fourth subnet id) and for the fourth it would be 65.255.255.255.

Once you know the ranges you just have to figure out which subnet range a given ip address falls within. Once you know which octets you are working within for the subnets it gets pretty easy to find the subnet the ip address is in.

Thanks bro. That does help, it falls into the theory that came to me the other day. I know how to do it with a chart but doing it like you did it above is faster. So I guess I'm truly now doing it all in my head. I'm working on doing them under 30 seconds now. Again, koodos!

Deathmage

So far I've painfully re-read up to chapter 9 so far in Todd's book and taking more notes than I did previously. I've gotten to the Serial DCE/DTE section and I still don't see a description of the buffer 1524 and what that means other than a vague term in regards to bandwidth. I may need to read a Cisco KB on this buffer 1524 to really see what it means.

Going to finish up the book reading by Friday and then just do chapter reviews leading up to the exam and starting this weekend going to re-do Chris Bryant Udemy Videos. I finally understand block size subnetting and will be using this on Subnetting.net to really focus in my subnetting skills.

Re-scheduled the 3rd exam for Saturday, August 8th @ 12 pm in NJ.

[Deleted User]

3rd time is the charm! At least it was for me. Good luck!

Mow

That's my wedding day! Good luck!

Stevecb06

I will be sitting for the CCENT the day before you. Hopefully we can both walk away with shiny new certs!

Deathmage

not too bad for the game, I'm a little slow to figure out the game at 1st, but it's pretty good for subnetting on the clock. and even then two of them I got correct but miss read the question, I put /23 but it wanted 255.255.254.0 and /11 instead of 255.224.0.0, I was like oo that's dumb...



anyone here have a membership over @ subnetting.net?

thomas_

I never used it, not even for the subnetting practice. I used an ip subnetting app on my iphone to practice. I actually didn't know they had study content until I visited their site just now.

Jon_Cisco

never looked at their study material I just used the practice test. I found when I rushed for a high score I did a lot worse. Just answer slowly and your speed will increase quickly.

Deathmage

Jon_Cisco wrote: »

never looked at their study material I just used the practice test. I found when I rushed for a high score I did a lot worse. Just answer slowly and your speed will increase quickly.

Ya I did, I also noticed that persistence is key with that website. takes a little while to see how the Class A's and B's are worded, once I figure it out eventually subnetting is easier.

Mooseboost

You have this for sure man. You are an absolutely inspiration with your dedication.

Deathmage

Mooseboost wrote: »

You have this for sure man. You are an absolutely inspiration with your dedication.

Thanks Moose! - I find when I schedule it makes me study harder, so I scheduled it.

Skandiluz

I read every page of this and I love how devoted you are. +1 for you. Good luck or your next attempt and we know you're going to destroy it this time!

Deathmage

Skandiluz wrote: »

I read every page of this and I love how devoted you are. +1 for you. Good luck or your next attempt and we know you're going to destroy it this time!

thanks bro, been spending about 15 minutes a day at work doing subnetting.net and then 20 minutes to an hour at home (but at home I get carried away and it takes away from books reading) just so I keep my skills sharp. I only use what I will be making on my white board as reference and that is the CIDR chart from /8 to /32 with the custom masks and then the block counts per octet.

I'm getting better and better at subnetting with speed and accuracy. I'll be super pissed if IP addresses IPv4 and v6 is not 100% on the next go through...

SpetsRepair

Subnetting video that really helped me

https://www.youtube.com/watch?v=rs39FWDhzDs

Jamesweb

Hey man, good luck on your 3rd try, you will knock it out this time for sure! I really admire your dedication to this and it really keeps me motivated as I progress towards my CCENT. I am still sort of stuck in Lammle's book in chapter 4 in subnetting mostly on class A's and B's but working it slowly and it really is clicking now.

Skandiluz

Deathmage wrote:

thanks bro, been spending about 15 minutes a day at work doing subnetting.net and then 20 minutes to an hour at home (but at home I get carried away and it takes away from books reading) just so I keep my skills sharp. I only use what I will be making on my white board as reference and that is the CIDR chart from /8 to /32 with the custom masks and then the block counts per octet.

I'm getting better and better at subnetting with speed and accuracy. I'll be super pissed if IP addresses IPv4 and v6 is not 100% on the next go through...

I'll be sinking a lot of time into networking myself. I have the foundation and I can do it but not nearly as well as I would like. Then again, I haven't done any subnetting in probably 4 months. LOL I wouldn't worry about the exam bro, you got this in the bag

SpetsRepair wrote:

Subnetting video that really helped me

https://www.youtube.com/watch?v=rs39FWDhzDs

Thanks for the link! I'll check it out sometime this weekend

DPN1

Have been playing that subnetting game on and off for the last 2 days in between studying (is it sad that I find it quite fun?) my high score without getting one wrong is 15 and was proper high score is 19 , i should probably get back to studying ip services now though, good luck on your exam next Saturday

Deathmage

I'm able to get this down to 10 to 45 seconds to do these depending upon how much thinking is involved with the /8's to /21's. It's just visualizing the numbers in my head. That number is probably less than 45 seconds but I just think and the number varies but 45 might be the max.

I like subnetting.net cause I can just do it for 5, 10, 15 minutes at a time, and really get the CIDR's in my skull. I hope all this subnetting pays off and subnetting on the exam is nearly instant but accurate. I sometimes notice that with a class A with a 4th octet I get the last IP wrong because I think of the interesting octet being in the 2nd or 3rd so that something I'm watching. But when the 2nd and 3rd octets I just remember like for a /17 as an example that it's a 128.1 not a .129 for a /25, it's those little things that I've been catching and getting better at. And then the broadcasts are something I'm getting better at, like for a 3rd octet it would be a 255.254 for say like a /17 but for a /25 it would just be a .255.











I'm sure I'm doing subnetting allot and it's not my weak point, I just want my study to be even and focused so I don't focus lesser on one area and more on another; that's the tricky part with studying Cisco I've found since they all really inner-twine with each other.

techfiend

Subnetting is the largest chunk of the test. If you think you've got it just spend a few minutes on subnetting.net a few times a day until you take the test.

Deathmage

Finished Todd's book for the CCENT part for the 5th time now. Doing Chris Bryant's Udemy Videos now for the remainder of the weekend.

mikeybinec

So if I tossed you a subnet question could you do it in about 30 seconds? Think fast: What's the block size of a slash 15? (/15 or 255.254.0.0)

(hint: the block size of a /15 is the same as a /23)

Deathmage

mikeybinec wrote: »

So if I tossed you a subnet question could you do it in about 30 seconds? Think fast: What's the block size of a slash 15? (/15 or 255.254.0.0)

(hint: the block size of a /15 is the same as a /23)

2? ....lol insert more words in this sentence cause I need a post response minimum words, lol!

logic: 255.128 is a block of 128, 255.192 is a block of 64, 255.224 is a block of 32, 255.240 is a block of 16, 255.248 is a block of 8, 255.252 is a block of 4.....soooo.... a 255.254 is a block of 2.

I've been loving subnetting.net now, once I understand the block sizes it's so much easier, just the math part sucks for .248 or .252 for say a 240 or 220 in the interesting octet.

techfiend

I don't know if it would help anyone else but 2 things that greatly improved my subnetting is. 4 = .240 and 10 to the power of 2 = 1024.

mikeybinec

techfiend wrote: »

and 10 to the power of 2 = 1024.

Hmmmm, wanna try again on that?

mikeybinec

Deathmage wrote: »

2?

there you go