Transcript Document

Lesson 21. IP Addressing
Objectives
At the end of this Presentation, you will
be able to:
• Explain the differences between Class A,
Class B, and Class C IP addresses.
• Given an IP address, determine what Class
of address it is.
• Explain the difference between the Network
ID and the Host ID portions of an IP
address.
• Explain the difference between Public and
Private IP Addresses.
• Identify broadcast, loop-back, and public
and private addresses.
Network+ Domains covered:
• 2.5
• 2.8
• 2.9
TCP/IP is:
• The Protocol of the Internet
• The number 1 protocol in the world for
moving data around
• A suite of over 100 protocols
• One of the protocols supported by Windows
9X, Windows NT, and Windows 2000/2003.
• One of the protocols supported by NetWare
5.0.
• The protocol of UNIX.
TCP/IP- A suite of protocols
• Internet Protocol (IP) - The protocol that
determines the Internet’s basic packet
structure and its addressing scheme.
• Transmission Control Protocol (TCP) - The
protocol that sets up a connection between
two hosts and ensures that data is passed
between them reliably.
IP Address
• A logical rather than physical address.
• How it is entered into your computer:
o
o
Manually, by you or the network administrator.
Automatically, via the Dynamic Host
Configuration Protocol (DHCP).
• Works at the Networking Layer of the OSI
model.
Each computer on a network
that uses the TCP/IP protocol
must have its own unique IP
address.
Converting an IP Address from
Binary to
Dotted-Decimal
1 1 0 0 1 1 0 1 1 1 0 1 0 0 0 0 0 1 1 11 0 0 1 0 0 0 0 0 1 01
205
208
113
205 .208 .113 .5
5
IP Address Classes
• Class A
• Class B
• Class C
The IP Address is divided into
two parts:
Network ID
Host ID
(Assigned by
InterNIC)
(Assigned
locally)
Class A IP Address
0 n n n n n n n x x x x x x x x x x x xx x x x x x x x x x xx
1 - 126
Network ID
(Assigned by
InterNIC)
Host ID
(Assigned locally)
Class B IP Address
1 0 n n n n n n n n nn n n n n x x x xx x x x x x x x x x xx
128 - 191
Network ID
(Assigned by
InterNIC)
Host ID
(Assigned locally)
Class C IP Address
1 1 0 n n n n n n n nn n n n n n n n nn n n n x x x x x x xx
192 - 223
Network ID
(Assigned by
InterNIC)
Host ID
(Assigned
locally)
Number of
Networks
Number of Hosts
per Network
Class A
126
16,777,214
Class B
16,384
65,534
Class C
2,097,152
254
Number of
Networks
Hosts/
Network
Theoretica
l
# of Hosts
Class A
126
16,777,214
2.1 Billion
Class B
16,384
65,534
1.1 Billion
Class C
2,097,152
254
0.5 Billion
Total
2,113,662
3.7 Billion
Range of
Network IDs
Class A
1-126
Class B
128-191
Class C
192-223
Network ID 127 is reserved for
testing.
• Loop back ID
• It is a “wild card” address for the local
device.
• It gives you a way of addressing the device
you are at without having to look up its
“real” IP address.
Address 255.255.255.255
• Reserved for broadcasts
• The packet is sent to all nodes on the LAN.
The other Network IDs
• Class D – 224 through 239. Used for
Multicasting. That is, it’s a way of
broadcasting to several hosts
simultaneously. Also called broadcast
addresses.
• Class E – 240 through 254. Used as
Experimental address blocks.
The first Octet identifies the
address Class.
•
•
•
•
•
•
•
•
0 Not Used
1-126 Class A
127 Loop back Address
128-191 Class B
192-223 Class C
224-239 Class D
240-254 Class E
255 Not generally used
Binary 1111 1111
Dotted Decimal 255
Broadcast Addresses by Class
• Class A Example 12.255.255.255
• Class B Example 128.128.255.255
• Class C Example 192.192.192.255
Conserving IP Addresses
• There are a limited number of IP addresses.
• The world is quickly running out of unused
IP addresses.
• The demand for new IP addresses continues
to grow.
• Several schemes have been devised to help
conserve the remaining supply of unused IP
addresses.
Definitions
• Enterprise – Any entity operating a TCP/IP
network.
• Host – A device within an enterprise that
has an IP address.
Three Categories of Enterprises
• Enterprises that do not require access to the
Internet.
• Enterprises that need unlimited access to
the Internet.
• Enterprises that need only limited access to
the Internet which can be handled by a
mediating gateway.
Internet
Private Network
• Not connected to Internet.
• Private network
• IP addresses are unique within the enterprise
but are not globally unique.
Private IP Addresses
• Used in private, isolated TCP/IP networks
that aren’t connected to the Internet.
• Allow private networks to have whatever
internal address structure they desires.
• Are not assigned by INTERNIC, but are
assigned by the local Network
Administrator.
• Are not unique, except within the private
network.
Host-A
9.0.0.9
Internet
Public Network
• Unlimited access to Internet.
• Public network
• IP addresses are globally unique.
Public IP Address
• A “legal” Internet address.
• Assigned by INTERNIC, either to you
directly, or indirectly through your Internet
Service Provider (ISP).
• “You can contact me at IP Address 193.
xxx.xxx.xxx.”
• It guarantees a globally unique IP address.
Private Network
Internet
Network Address
Translator (NAT)
Private IP Addresses
• The Internet Assigned Numbers Authority
(IANA) has reserved three blocks of the IP
address space for private internets:
o
o
o
10.0.0.0 through 10.255.255.255
172.16.0.0 through 172.31.255.255
192.168.0.0 through 192.168.255.255
Why Private IP Addresses?
• Inevitably, the private address will
eventually get connected to the Internet.
• By making these private addresses known,
gateways and routers can be programmed to
filter out private IP addresses thereby
keeping them off of the Internet.
• These private IP addresses are not allowed
to be routed on the Internet.
Identify the network Class for
these IP Addresses.
•
•
•
•
•
127.0.0.1
1.0.0.1
128.173.129.113
173.129.116.100
193.0.0.1
Identify the network Class for
these IP Addresses.
•
•
•
•
•
127.0.0.1 Loop back address
1.0.0.1 Class A
128.173.129.113 Class B
173.129.116.100 Class B
193.0.0.1 Class C
Which of the following is a
private IP address?
•
•
•
•
10.123.123.123
172.17.123.123
192.168.123.123
224.192.123.123
Which of the following is a
private IP address?
•
•
•
•
10.123.123.123 Private
172.17.123.123 Private
192.168.123.123 Private
224.192.123.123 Public - Multicast
• Explain the differences between Class A,
Class B, and Class C IP addresses.
• Given an IP address, determine what Class
of address it is.
• Explain the difference between the Network
ID and the Host ID portions of an IP
address.
• Explain the difference between Public and
Private IP Addresses.
• Identify broadcast, loop-back, and public
and private addresses.