Protocols_2 - Computing Sciences and Mathematics ...

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Oct 24, 2013 (3 years and 11 months ago)

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1

Protocols


Part 2

ITEC 370

George Vaughan

Franklin University

2

Sources for Slides


Material in these slides comes primarily
from course text, Guide to Networking
Essentials,Tomsho, Tittel, Johnson (2007).


Other sources are cited in line and listed in
reference section.

3

TCP/IP and OSI Models

4

Some Simple Binary Arithmetic


Tomsho, Tittel, Johnson (2007)



Four kinds of binary calculations:


Converting between binary and decimal


Converting between decimal and binary


Understanding how setting high
-
order bits to
the value of 1 in 8
-
bit binary numbers
corresponds to specific decimal numbers


Recognizing the decimal values for numbers
that correspond to low
-
order bits when set to 1

5

Converting Decimal to Binary


Tomsho, Tittel, Johnson (2007)






125 is converted to binary as follows:


125 divided by 2 equals 62, remainder 1


62 divided by 2 equals 31, remainder 0


31 divided by 2 equals 15, remainder 1


15 divided by 2 equals 7, remainder 1


7 divided by 2 equals 3, remainder 1


3 divided by 2 equals 1, remainder 1


1 divided by 2 equals 0, remainder 1

6

Converting Binary to Decimal


Tomsho, Tittel, Johnson (2007)


To convert 11010011 to decimal:

1.
Count the total number of digits in the number (8)

2.
Subtract one from the total (8
-

1 = 7)

3.
That number (7) is the power of 2 to associate with
the highest exponent for two in the number

4.
Convert to exponential notation, using all the digits
as multipliers

5.
11010011, therefore, converts to:

7

High
-
Order Bit Patterns


Tomsho, Tittel, Johnson (2007)


8

Low
-
Order Bit Patterns


Tomsho, Tittel, Johnson (2007)


9

Types of IP Addressing


The demarcation point in the 32 bit
address between network ID and host ID
depends on addressing scheme:


Class Based Addressing generally uses a
byte boundary as the dividing point


Classless Based Addressing uses a bit
boundary.

10

Class Based IP Addressing

(Cisco


IP Addressing, n.d.).

Used less frequently now, CIDR preferred

11

Special IP Addresses


Information on this slide from
http://www.iana.org/faqs/abuse
-
faq.htm


"Private Use" IP addresses:


10.0.0.0
-

10.255.255.255


172.16.0.0
-

172.31.255.255


192.168.0.0
-

192.168.255.255


"Autoconfiguration" IP Addresses:


169.254.0.0
-

169.254.255.255


used automatically by some PCs and Macs when


They are configured to use IP


Do not have a static IP Address assigned


And are unable to obtain an IP address using DHCP.


"Loopback" IP addresses:


127.0.0.0
-

127.255.255.255


Each computer on the Internet uses 127.0.0.0/8 to identify itself, to itself.


127.0.0.0 to 127.255.255.255 is earmarked for what is called "loopback".


This construct allows a computer to establish/validate its IP stack.


Most software only uses 127.0.0.1 for loopback purposes

12

Classless Interdomain Routing
(CDIR)


Division between Network and Host ID is at bit level.


Example: 192.203.187.0/27


IP address is: 192.203.187.0


‘/27’ indicates that:


First 27 bits define Network ID


Last 5 bits define Host ID (defines size of subnet)


Subnet Mask =


(binary) 11111111 11111111 11111111 111
00000


(decimal) 255.255.255.224


Subnet Mask defines Host ID size


1’s used to define which bits belong to Network ID


0’s used to define which bits belong to Host ID


Subnet Mask is assigned to host at same time that IP address is
assigned.


13

CDIR (Cont.)


Mapping class based IP addressing to
CDIR:


Class A submask = 255.0.0.0


Class B submask = 255.255.0.0


Class C submask = 255.255.255.0


All hosts in same network must use same
subnet mask.

14

Subnetting with Classless IP Addressing: Example 1

15

Subnetting with Classless IP Addressing: Example 1
(Continued)

16

Subnetting with Classless IP Addressing: Example 2

17

Subnetting with Classless IP Addressing: Example 2
(Continued)

18

IP Addressing Tools


Looking up an IP address:


http://psacake.com/web/eg.asp


http://www.faqs.org/rfcs/rfc1812.html



Subnetting:


http://ccna.exampointers.com/subnet.phtml


19

IPv6 Address Scheme


Hexidecimal grouped in 16 bit sections:


2001:1b20:302:442a:110:2fea:ac4:2b


Leading zeroes are eliminated


2 or more 16 bit fields of all zeros can be ignored:


2001:260:0:0:0:2ed3:340:ab (long form)


2001:260::2ed3:340:ab (short form)


IPv6 has 3 parts:


20

References


Tomsho, Tittel, Johnson (2007).
Guide to Networking
Essentials.

Boston: Thompson Course Technology.

Odom, Knott (2006).
Networking Basics: CCNA 1
Companion Guide
. Indianapolis: Cisco Press

Wikipedia (n.d.).
OSI Model
. Retrieved 09/12/2006 from
http://en.wikipedia.org/wiki/OSI_Model

Cisco


IP Addressing (n.d.). IP Addressing. Retrieved
09/27/2006 from
http://cco.cisco.com/warp/public/701/3.html#figone

IANA (n.d.)
Abuse Issues and IP Addresses .
Retrieved
11/11/06 from
http://www.iana.org/faqs/abuse
-
faq.htm