IP Addressing & Subnetting Made Easy - dronacharya

72 Pages·2014·0.94 MB·English

IIPP AAddddrreessssiinngggg &&
SSuubbnneettttiinngg MMaaddee EEaassyy
WWoorrkkiinngggg wwiitthh IIPP
AAddddrreesssseess
IInnttrroodduuccttiioonn
You can probably work with decimal
(cid:132)
nnuummbbeerrss mmuucchh eeaassiieerr tthhaann wwiitthh tthhee
binary numbers needed by the
ccoommppuutteerr.
Working with binary numbers is time-
(cid:132)
consumiing && error-prone.
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OOcctteettss
The 32-bit IP address is broken up into
(cid:132)
44 oocctteettss, wwhhiicchh aarree aarrrraannggeedd iinnttoo aa
dotted-decimal notation scheme.
AAn octtett iis a sett off 88 bbiitts && nott a
(cid:132)
musical instrument.
Example of an IP version 4:
(cid:132)
172.64.126.52
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TThhiinnkkiinngg iinn BBiinnaarryy
The binary system uses only 2
(cid:132)
vvaalluueess “00 && 11” ttoo rreepprreesseenntt
numbers in positions representing
iinnccrreeaassiinngg ppoowweerrss ooff 22.
We all are accustomed to thinking
(cid:132)
&& workkiing iin tthhe ddeciimall systtem,
which is based on the number 10.
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TThhiinnkkiinngg iinn BBiinnaarryy
((CCoonntt..))
To most humans, the number 124
(cid:132)
representts 110000 ++ 2200 ++ 44.
To the compputer, this number is
(cid:132)
1111100, which is 64 (26) + 32 (25)
+ 1166 ((224)) + 88 ((223)) + 44 ((222)) + 00 + 00
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Each position in a binary number
(cid:132)
representts, riighhtt tto llefftt, a power off
two beginning with 20 & increasing
by one power as it moves left: 20,
21, 22, 24, etc.
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CCoonnvveerrttiinngg ttoo DDeecciimmaall
You’ll need to convert binary to
(cid:132)
ddeecciimmaall && vviiccee vveerrssaa ttoo ccoommppuuttee
subnets & hosts.
SSo, iitt’’s ttiime ffor a quiickk reviiew llesson
(cid:132)
in binary-to-decimal conversion.
There are 8 bits in an octet & each bit
(cid:132)
can only be a 1 or a 0.
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CCoonnvveerrttiinngg ttoo DDeecciimmaall
((CCoonntt..))
What then do you suppose is the largest
(cid:132)
ddeecciimmaall nnuummbbeerr tthhaatt ccaann bbee eexxpprreesssseedd
in an octet?
Eight 1’s (1111 1111)
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CCoonnvveerrttiinngg ttoo DDeecciimmaall
((CCoonntt..))
Now, for double the money, what is its
(cid:132)
equivalent decimal value?
27 26 25 24 23 22 21 20
1 1 1 1 1 1 1 1
128 64 32 16 8 4 2 1
The binary number 1111 1111 converts into the
decimal number:
128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = 255
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