page 1 - © richard l. goldman ip address ©richard l. goldman january 10, 2002
TRANSCRIPT
Page 2 - © Richard L. Goldman
IP Address• An IP address is a 32-bit binary number.
00000000000000000000000000000000• It is made up of four 8-bit binary numbers
separated by periods (dotted decimal notation).00000000.00000000.00000000.00000000
• Each 8-bit binary number is called an octet.• The maximum decimal value for each octet is 255.
111111112 = 25510
• Each octet is represented with a decimal value from 0to 255 (256 different numbers per octet).
0 . 0. 0. 0 to 255.255.255.255
Page 3 - © Richard L. Goldman
Network and Host Addresses• An IP address is divided in to two parts:• Network Address:
– The Network Address indicates which network the IP address belongs to.
– This address is used to route IP datagrams throughout a TCP/IP internetwork.
• Host Address:– The Host Address indicates which particular
device within a specific network the IP address belongs to.
Page 4 - © Richard L. Goldman
Network/Host Portions
• The Network Address is always the first part of the IP address followed by the Host Address.
• The number of digits assigned to the Network and Host portions of the IP address varies depending on the numbers of computers in a network.
??? . ??? . ??? . ???
??? . ??? . ??? . ???
??? . ??? . ??? . ???
Host AddressNetwork Address
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Large Networks (Class A Networks)
• Class A networks will have many digits assigned to the Host portion of the IP address. (Leaving only a few digits for the Network portion.)
??? . ??? . ??? . ???
Network Address Host Address
Page 6 - © Richard L. Goldman
Medium Sized Networks (Class B Networks)
• Class B networks will have half of the digits assigned to the Host portion of the IP address. (Leaving half of digits for the Network portion.)
??? . ??? . ??? . ???
Network Address Host Address
Page 7 - © Richard L. Goldman
Small Networks (Class C Networks)• Class C networks will have only a few digits
assigned to the Host portion of the IP address. (Which leaves a lot of digits left for the Network portion.)
??? . ??? . ??? . ???
Network Address Host Address
Page 8 - © Richard L. Goldman
Classes• IP addresses are divided into classes. The first
three classes represent unicast (point-to-point) addresses:
• Class A
• Class B
• Class C
• The classes are based on the number of host addresses that can be assigned.
Page 9 - © Richard L. Goldman
Class A Network Address• A Class A address uses only the first octet for
the network address.
• The network portion of a Class A address can range from 000 to 126.
• This gives a maximum of 126 different Class A network addresses. (All 0’s can not be used for a network address because it is a reserved number.)
0 . ??? . ??? . ???
Network Address Host Address
Lowest Number
Highest Number 126 . ??? . ??? . ???
Page 10 - © Richard L. Goldman
Class A Host Address• A Class A address uses the last three octets
for host addresses.
• The host portion of a Class A address can range from 000.000.001 to 255.255.254.
• This gives a maximum of 16,777,214 different host addresses within a single Class A network.
??? . 0 . 0 . 1
Network Address Host Address
Lowest Number
Highest Number ??? . 255 . 255 . 254
Page 11 - © Richard L. Goldman
Class B Network Address• A Class B address use the first two octets
for network addresses.
• The network portion of a Class B address can range from 128.000 to 191.255.
• This gives a maximum of 16,382 different Class B network addresses.
128 . 0 . ??? . ???
Network Address Host Address
Lowest Number
Highest Number 191 . 255 . ??? . ???
Page 12 - © Richard L. Goldman
Class B Host Address• A Class B address use the last two octets
for host addresses.
• The host portion of a Class B address can range from 000.001 to 255.254.
• This gives a maximum of 65,534 different host addresses within a single Class B network.
??? . ??? . 0 . 1
Network Address Host Address
Lowest Number
Highest Number ??? . ??? . 255 . 254
Page 13 - © Richard L. Goldman
Class C Network Address• A Class C address use the first three octets
for network addresses.
• The network portion of a Class C address can range from 192.000.000 to 223.255.255.
• This gives a maximum of 2,097,150 different Class C network addresses.
192 . 0 . 0 . ???
Network Address Host Address
Lowest Number
Highest Number 223 . 255 . 255 . ???
Page 14 - © Richard L. Goldman
Class C Host Address• A Class C address uses only the last octet
for host addresses.
• The host portion of a Class C address can range from 001 to 254.
• This gives a maximum of 254 different host addresses within a single Class C network.
??? . ??? . ??? . 1
Network Address Host Address
Lowest Number
Highest Number ??? . ??? . ??? . 254
Page 15 - © Richard L. Goldman
Other Network Classes
• Class D addresses designate host nodes that receive broadcast messages (Multicasting).– 224 through 239– Addresses that are in the range of 224.0.0.0 to
225.0.0.0 are experimental, or are reserved for future use and don't define any network.
• Class E & F addresses are reserved for experimental and future use.– 240 through 254
Page 16 - © Richard L. Goldman
SummaryClass Range
(1st Octet)
Max Number of Networks
Max Number of Hosts
A 0-126 126 16,777,214
B 128-191 16,382 65,534
C 192-223 2,097,150 254
D 224-239 (Multicasting)
E 240-254 (Research)
The network class of an IP address can be determined by noting which range that the first octet falls within.
Page 17 - © Richard L. Goldman
Special IP Addresses
• Broadcast (Local network segment only)
• Reserved
• Loopback Test127. 0. 0. 1
0. 0. 0. 0
255.255.255.255
Page 18 - © Richard L. Goldman
Private Network IP Addresses• The IANA (Internet Assigned Numbers Authority) has
designated the following IP Addresses for use within a private network.
• Class A:
10. 0. 0. 0 through 10.255.255.255• Class B:
172. 16. 0. 0 through 172. 31.255.255• Class C:
192.168. 0. 0 through 192.168.255.255
• External routers should disregard these addresses and not publish their location
Page 19 - © Richard L. Goldman
Leading Binary Bit(s) of IP Classes
Class Binary
A 0
B 10
C 110
D 1110
E 11110
Page 20 - © Richard L. Goldman
IP Address QuizClass Range # Nets #Hosts
A Public 0. 0. 0. 0 – 126.255.255.255 126 17M
B Public 128. 0. 0. 0 – 191.255.255.255 16K 65K
C Public 192. 0. 0. 0 – 223.255.255.255 2M 254
D 224. 0. 0. 0 – 239.255.255.255
E 240. 0. 0. 0 – 254.255.255.255
A Private 10. 0. 0. 0 – 10.255.255.255 1 17M
B Private 172. 16. 0. 0 – 172. 31.255.255 16 65K
C Private 192.168. 0. 0 – 192.168.255.255 256 254
Loopback 127. 0. 0. 1 – 127.255.255.255
Broadcast 255.255.255.255
IP Address Review
Page 21 - © Richard L. Goldman
IP Address QuizClass Range # Nets #Hosts
A Public
B Public
C Public
D
E
A Private
B Private
C Private
Loopback
Broadcast
IP Address Quiz
Page 22 - © Richard L. Goldman
IP Address QuizClass Range # Nets #Hosts
A Public 0. 0. 0. 0 – 126.255.255.255 126 17M
B Public 128. 0. 0. 0 – 191.255.255.255 16K 65K
C Public 192. 0. 0. 0 – 223.255.255.255 2M 254
D 224. 0. 0. 0 – 239.255.255.255
E 240. 0. 0. 0 – 254.255.255.255
A Private 10. 0. 0. 0 – 10.255.255.255 1 17M
B Private 172. 16. 0. 0 – 172. 31.255.255 16 65K
C Private 192.168. 0. 0 – 192.168.255.255 256 254
Loopback 127. 0. 0. 1 – 127.255.255.255
Broadcast 255.255.255.255
IP Address Quiz Answers