Addressing of Internet Koji OKAMURA Kyushu University.

Addressing of Internet

Koji OKAMURA

Kyushu University

Quiz

• An university use 192.168.0.0/22 for whole campus network and there are three departments in the university; A,B,C.– Department A uses 192.168.0.0/23– Department B uses 192.168.2.0/26– Department C has about 250 PCs. Which

network address should be assigned to Department C?

Information Network 2

Addressing of Internet Protocol

Information Network 3

Router

Router

Router

Addressing of Internet Protocol

Information Network 4

1 2 3

Router1 2 3

Router

Router

1 2 3

1 2 3

#1

#2

#3

#4

#5

#6

Internet Address = Network ID (#?) + Host ID (1~3)

Network IP address is IP address of which all of host ID’s bit is 0.Broadcast address is IP address of which all of host ID’s bit is 1.

Information Network 5

Class A,B,C

01000000101010000000101000100001

10000000101010000000101000100001

11000000101010000000101000100001

Class A

Class B

Class C

Information Network 6

Class A

01000000101010000000101000100001

Class A

•Network Address•1.0.0.0 – 127.0.0.0

•Host Address•1.0.0.1 – 1.255.255.254

Information Network 7

Class B

10000000101010000000101000100001

Class B

•Network Address•128.0.0.0 – 191.255.0.0

•Host Address•128.0.0.1 – 128.0.255.254

Information Network 8

Class C

11000000101010000000101000100001

Class C

•Network Address•192.0.0.0 – 223.255.255.0

•Host Address•192.0.0.1 – 192.0.0.254

Information Network 9

Class D(Multicast)

11100000101010000000101000100001

Class D

•Network Address•224.0.0.0 – 239.255.255.255

Information Network 10

クラスレス(Classless Inter-Domain Routing:CIDR)

11000000101010000000101000100001

Class C

11000000101010000000101000100001

Classless

192.168.10.33/22

Address Assignment based on Class

Class A2^7

Class A2^7

Class B2^14

Class B2^14

Class C2^21

Class C2^21

CIDR:Classless Inter-Domain Routing

クラス A2^7

クラス A2^7

クラス B2^14

クラス B2^14

クラス C2^21

クラス C2^21

Prefix = network address + length

Many Prefixes268,500

What’s the problem of many prefixes?

Information Network 13

ISP ISP

ISP ISP

University

A border BGP router must imports full routing information from all of peering ISP.