• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/5

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

5 Cards in this Set

  • Front
  • Back
  • 3rd side (hint)
Subnet Classes
First octet ranges
Subnet masks
Class A
First octet: 1-126
Mask: 255.0.0.0

Class B
First octet: 128-191
Mask: 255.255.0.0

Class C
First octet: 192-223
Mask: 255.255.255.0

Class D
First octet: 224-247

Class E
First octet: 248-255
Classes are defined according to where the first zero bit is found in the first octet's four left most bits (first nibble).

In class A it is in the 7th bit. In class B it is in the 6th bit. In class C it is in the 5th bit.
In class D it is in the 4th bit.
In class E no zero bits in left most nibble.
Powers of 2
2^0 = 1
2^1 = 2
2^2 = 4
2^3 = 8
2^4 = 16
2^5 = 32
2^6 = 64
2^7 = 128
2^8 = 256
2^9 = 512
2^10 = 1024 or 1K
2^11 = 2048 or 2K
2^12 = 4096 or 4K
2^13 = 8192 or 8K
2^14 = 16,384 or 16K
2^15 = 32,768 or 32K
2^16 = 65,536 or 64K
X^0 is 1 for all values of X.
Each line is double the preceding line.
Formula to calculate number of hosts given number of host bits in the subnet
2^n-2
Where "n" is the number of host bits in the subnet
Usable host addresses for host bits
2 = 4-2 = 2
3 = 8-2 = 6
4 = 16-2 = 14
5 = 32-2 = 30
6 = 64-2 = 62
7 = 128-2 = 126
8 = 256-2 = 254
9 = 512 ~ 500
10 = 1024 ~ 1000
11 = 2048 ~ 2000
12 = 4096 ~ 4000
13 = 8192 ~ 8000
14 = 16,384 ~ 16,000
15 = 32,768 ~ 32,000
16 = 65,536 ~ 64,000
The right column can be added to the powers of 2 table for convenience.
Class C Subnet masks, number of networks, number of hosts
255.255.255.0 1 254
255.255.255.128 2 126
255.255.255.192 4 62
255.255.255.224 8 30
255.255.255.240 16 14
255.255.255.248 32 6
255.255.255.252 64 2