# Protocols_2 - Computing Sciences and Mathematics ...

Networking and Communications

Oct 24, 2013 (4 years and 6 months ago)

93 views

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

Used less frequently now, CIDR preferred

11

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

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.

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)

(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

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

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

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