Brain **** before start of exam

Before the start of the exam use your tutorial time to do a brain **** to your laminated sheet. This will help you save time during the exam. Helpful things that I wrote down were:
- powers of 2 (2 4 8 16 32 64 128 256 512)
- 128 64 32 16 8 4 2 1 with 192 over 64, 224 over 32, 240 over 16, 248 over 8, 252 over 4, 254 over 2, 255 over 1
- range of each IP Class and default subnet mask
- private IP addresses
- OSI Layers and matched encapsulation (data, segment, packet, frame & bits to correct layers)

Even though you have this memorized you can get confused. Instead of trying to remember you can focus on other issues. Anyone else have something to add?

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Comments

isadore

Did you perhaps take a class in Roseville for this ??

2Tahoe

I completed all 4 semesters of the Cisco Academy with a college not too far from Roseville. Why do you ask?

cresswells

Don’t throw away easy marks on IP addressing by getting bit boundaries wrong. Write this down on the sheet given to you BEFORE you start the test.
8192 4096 2048 1024 512 Hosts beyond 4th octet
128 192 224 240 248 252 254 255 Subnet mask
256 128 64 32 16 8 4 2 # Hosts (Subtract 2)
2 4 8 16 32 64 128 256 # Subnets
128 64 32 16 8 4 2 1

Lerman

Do they still give you a sheet for the 801 exam? I thought I had heard somewhere that they weren't doing that for the newest exam.

ConfoundedBridge

I was hoping to see more info in here on what people found helpful to write down before the exam.

What I've used/will use:
[list:26f751eb2a]
I write down the "16" networks (0,16,32,...) along the edge.
I also write down the binary values for each bit in within an octet (128, 64, 32, 16, 8, 4, 2, 1).
For my next (and hopefully last) test, I'll be adding /25, /26, ..., /30 above the bit values I just mentioned. Doing this will allow me to more quickly identify there are 14 hosts in a /28, etc.
I'll probably also add subnet mask values too... I'm comfortable up to 248, but manage to make stupid mistakes with 252 and 254.

So, it'd look something like this:
```
/25  /26  /27  /28  /29  /30
128   64   32   16    8    4    2    1
128  192  224  240  248  252  254
```

[/list:u:26f751eb2a]

Questions/What do you use?[list:26f751eb2a]
I don't recall having to need the powers of 2 table... can anyone comment on what they've found it useful for?
Has anyone found a wildcard mask chart handy? How have you set it up and used it?
Anyone know of other charts (a thread here, or another site) that are handy?

[/list:u:26f751eb2a]

Thanks.

schwarztrader

Q - I don't recall having to need the powers of 2 table... can anyone comment on what they've found it useful for?

A - I too write this down (even though its easy math) just so I can find out the correct amount of hosts/networks when asked to determine the correct mask.

2N-2

alastair

I just passed my CCNA exam, and relied heavily on my brain ****. Here's what I wrote down.

Multiples of 16: 16, 32, 48, 64, etc up to 256. Really handy for quickly working out valid subnets. Of course you don't always have a block size of 16 but with this you can interpolate easily.

Table of subnets:
Mask bits: /24, /25, /26
decimal versions: 0, 128, 192, 224, etc
block size: (256 - mask)
number of subnets (incl. subnet zero): 0, 2, 4, etc
number of valid hosts (2^bits - 2): 254, 126, 62, etc

Powers of 2 up to 2^14 (for use when subnetting class B addresses)

The most important thing here is to maximise your time spent thinking about the theory, double-checking your answers, and less about the arithmetic. I found the brain **** to be a life saver, and referred to it constantly.

I finished 16 mins early and there's no way I could have done this without having all the numbers laid out in front of me.

brandonzz

i used the same subnet chart on my intro test today saved me a tons of time finished with like 30mins left. i just wished on the test it would you which # question you were on you had an idea how far along you were.