IP Addressing and Routing

1
IP Addressing and Routing
2
Objectives

1. Addressing and routing overview
2. Classful IP addressing
3. Classless IP addressing (subnetting)
4. IP routing

3
1. Addressing Routing Overview
4
Network Layer Path Determination
5
Network Layer Path Determination
Which Path?

• Network layer functions to find the best path
  through the internetwork

6
Communicate Path
5
2
9
6
4
8
10
11
3
1
7

• Addresses represent the path of media connections
  (wires)

7
Addressing Network and Host
Network
Host
1
1 2 3
2.1
1.2
3.1
1.1
1.3
2
1
3
1

• Network addressPath part used for routing
• Host addressSpecific port or device on the
  network

8
TCP/IP Network Addressing
32 bits
8,16, or 24 bits from IANA
Varies with subnet mask
Network
Host
Ethernet
9
Router Interface Addressing
E110.2.5.3
10.2.0.0
10.1.0.0
E210.3.15.14
E010.1.23.7
10.3.0.0

• Network portion of address used to make path
  selections

DestinationNetwork
Router Port
Router Address
10.1.0.0
E0
10.1.23.7
10.2.0.0
E1
10.2.5.3
10.3.0.0
E2
10.3.15.14
10
Router Interface Addressing
E110.2.5.3
10.2.0.0
10.1.0.0
E210.3.15.14
E010.1.23.7
10.3.0.0

• Network portion of address used to make path
  selections

DestinationNetwork
Router Port
Router Address
10.1.0.0
E0
10.1.23.7

• Node portion of address refers to router port

10.2.0.0
E1
10.2.5.3
10.3.0.0
E2
10.3.15.14
11
Router Interface Addressing
E110.2.5.3
10.2.0.0
10.1.0.0
E210.3.15.14
E010.1.23.7
10.3.0.0

• Network portion of address used to make path
  selections

DestinationNetwork
Router Port
Router Address
10.1.0.0
E0
10.1.23.7

• Node portion of address refers to router port
• On router each interface has different IP address

10.2.0.0
E1
10.2.5.3
10.3.0.0
E2
10.3.15.14
12
Routing Tables In Routers
10.1.0.0
10.2.0.0
10.3.0.0
10.4.0.0
A
B
C
S1
S0
S0
S1
S0
S1
Routing Table
Routing Table
Routing Table
10.1.0.0
10.2.0.0
0
10.3.0.0
0
0
S0
10.2.0.0
10.3.0.0
0
10.4.0.0
S1
0
0
10.3.0.0
1
10.4.0.0
1
10.2.0.0
1
10.4.0.0
2
10.1.0.0
1
10.1.0.0
2

• Router uses the best path to destination

13
Analogy
Network Street name
Host Building number
Router Crossing
Routing table Direction signs
Packets Taxi with passenger
Destination IP address Street address
Please take me to Oxford Street 23!
14
2. Classful IP Addressing
15
TCP/IP Addresses
UNIX Host
UNIX Host
Internet
TCP/IP
Company A
Company B

• Unique addressing allows seamless communication
  between end stations
• Path choice is based on location
• Location is represented by an address

16
Introduction to TCP/IP Addresses
UNIX Host
UNIX Host
Company A
Company B

• Unique addressing allows seamless communication
  between end stations
• Path choice is based on location
• Location is represented by an address

17
Introduction to TCP/IP Addresses
UNIX Host
UNIX Host
Company A
Company B

• Unique addressing allows seamless communication
  between end stations
• Path choice is based on location
• Location is represented by a network address

18
IP Addressing
19
IP Addressing
20
Dotted Decimal Notation
21
Dotted Deciaml Notation
22
Binary Conversion Table
23
IP Address Classes

• Class A
• Class B
• Class C
• Class D for multicast
• Class E for research

N Network number H Host number
24
IP Address Bit Patterns
25
IP Address Bit Patterns
26
IP Address Bit Patterns
27
IP Address Classes
28
Number of Networks and Hosts
29
Recognizing Classes in IP Addresses (First Octet
Rule)
High OrderBits
Octet inDecimal
AddressClass
0 10 110
1 126 128 191 192 223
A B C
30
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
128.63.2.100
201.222.5.64
192.6.141.2
130.113.64.16
256.241.201.10
31
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
128.63.2.100
201.222.5.64
192.6.141.2
130.113.64.16
256.241.201.10
32
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
128.63.2.100
201.222.5.64
192.6.141.2
130.113.64.16
256.241.201.10
33
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
201.222.5.64
192.6.141.2
130.113.64.16
256.241.201.10
34
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
201.222.5.64
192.6.141.2
130.113.64.16
256.241.201.10
35
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
201.222.5.64
192.6.141.2
130.113.64.16
256.241.201.10
36
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
192.6.141.2
130.113.64.16
256.241.201.10
37
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
192.6.141.2
130.113.64.16
256.241.201.10
38
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
192.6.141.2
130.113.64.16
256.241.201.10
39
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
0.0.0.64
192.6.141.2
130.113.64.16
256.241.201.10
40
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
0.0.0.64
192.6.141.2
C
130.113.64.16
256.241.201.10
41
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
0.0.0.64
192.6.141.2
C
192.6.141.0
130.113.64.16
256.241.201.10
42
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
0.0.0.64
192.6.141.2
C
192.6.141.0
0.0.0.2
130.113.64.16
256.241.201.10
43
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
0.0.0.64
192.6.141.2
C
192.6.141.0
0.0.0.2
130.113.64.16
B
256.241.201.10
44
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
0.0.0.64
192.6.141.2
C
192.6.141.0
0.0.0.2
130.113.64.16
B
130.113.0.0
256.241.201.10
45
Written Exercise IP Address Classes
Address
Class
Network
Host
10.2.1.1
A
10.0.0.0
0.2.1.1
128.63.2.100
B
128.63.0.0
0.0.2.100
201.222.5.64
C
201.222.5.0
0.0.0.64
192.6.141.2
C
192.6.141.0
0.0.0.2
130.113.64.16
B
130.113.0.0
0.0.64.16
256.241.201.10
46
Written Exercise IP Address Classes
47
Host Addresses
10
1
1
.
1 .
.
Network
Host
172.16.2.1
10.1.1.1
E0
E1
172.16.3.10
10.250.8.11
172.16.12.12
10.180.30.118
IP 172.16.2.1
IP 10.6.24.2
Routing Table
Network
Interface
172.16
12
12
.
.
Network
Host
172.16.0.0 10.0.0.0
E0 E1
48
3. Classless IP Addressing (subnetting)
49
Addressing without Subnets
172.16.0.0

• Network 172.16.0.0

50
Addressing with Subnets
172.16.3.0
172.16.4.0
172.16.1.0
172.16.2.0

• Network 172.16.0.0

51
Subnet Addressing
172.16.2.200
172.16.3.5
E0
E1
172.16.2.2
172.16.3.100
172.16.2.160
172.16.3.150
Routing Table
Subnet
Interface
172.16.0.0 172.16.0.0
E0 E1
52
Subnet Addressing
172.16.2.200
172.16.3.5
E0
E1
172.16.2.2
172.16.3.100
172.16.2.160
172.16.3.150
IP 172.16.2.1
IP 172.16.3.1
Routing Table
Subnet
Interface
172.16
2
160
.
.
Network
Host
172.16.0.0 172.16.0.0
E0 E1
Subnet
53
Subnet Addressing
172.16.2.200
172.16.3.5
E0
E1
172.16.2.2
172.16.3.100
172.16.2.160
172.16.3.150
IP 172.16.2.1
IP 172.16.3.1
New Routing Table
Subnet
Interface
172.16
2
160
.
.
Network
Host
172.16.2.0 /24 172.16.3.0 /24
E0 E1
Subnet
54
Subnet Mask
IPAddress
55
Subnet Mask
IPAddress
Network
Host
DefaultSubnetMask /16
56
Subnet Mask
IPAddress
Network
Host
DefaultSubnetMask /16
Network
Subnet
Host
8-bitSubnetMask /24
Use host bits, starting at the high order bit
position
57
CIDR Notation for Subnets
CIDR notation
CIDR Classless Inter Domain Routing
58
Subnet Mask without Subnets
Network
Host
172.16.2.160
10101100
00010000
10100000
00000010
11111111
11111111
00000000
255.255.0.0
00000000
00000000
00000000
10101100
00010000
172
16
0
0

• CIDR notation /16

59
Subnet Mask with Subnets
Network
Host
Subnet
172.16.2.160
10101100
00010000
10100000
00000010
255.255.255.0
11111111
11111111
11111111
00000000
00000010
00000000
10101100
00010000
172
16
2
0

• CIDR notation /24

60
IP Subnetting Example
189.168. 12. 55 255.255.255.224 --------------- 18
9.168. 12. 32 1011 1101 . 1010 1000 . 0000 1100
. 0011 0111 1111 1111 . 1111 1111 . 1111 1111 .
1110 0000 ----------------------------------------
----- 1011 1101 . 1010 1000 . 0000 1100 . 0010
0000

• CIDR notation /27

61
Written Exercise Subnet Masks
62
Written Exercise Subnet Masks
63
Written Exercise Subnet Masks
64
Written Exercise Subnet Masks
65
Written Exercise Subnet Masks
66
Written Exercise Subnet Masks
67
Written Exercise Subnet Masks
68
Subnet Planning
20 subnets 5 hosts per subnet Class C address
201.222.5.0
Other subnets
69
Class C Subnet Planning Example
IP Host Address 201.222.5.121 Subnet Mask
255.255.255.248
Network
Subnet
Host
201.222.5.121
11001001
11011110
00000101
01111 001
255.255.255.248
11111111
11111111
11111111
11111 000
Subnet
11001001
11011110
00000101
01111 000
201
222
5
120

• Subnet Address 201.222.5.120
• Host Addresses 201.222.5.121201.222.5.126
• Broadcast Address 201.222.5.127
• Five Bits of Subnetting

• CIDR notation /29

70
Broadcast Addresses
172.16.3.0
172.16.4.0
172.16.1.0
172.16.2.0
71
Broadcast Addresses
172.16.3.0
172.16.4.0
172.16.1.0
172.16.2.0
X
255.255.255.255 (Local network broadcast)
72
Broadcast Addresses
172.16.3.0
172.16.4.0
172.16.1.0
172.16.2.0
172.16.3.255 (Directed broadcast)
X
255.255.255.255 (Local network broadcast)
73
Special IP Address Forms
74
Subnet Planning
20 subnets 5 hosts per subnet Class C address
201.222.5.0
201.222.5.16
Other subnets
201.222.5.32
201.222.5.48

• CIDR notation /29

75
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
15.16.193.6
255.255.248.0
128.16.32.13
255.255.255.252
153.50.6.27
255.255.255.128
76
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
15.16.193.6
255.255.248.0
128.16.32.13
255.255.255.252
153.50.6.27
255.255.255.128
77
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.56
15.16.193.6
255.255.248.0
128.16.32.13
255.255.255.252
153.50.6.27
255.255.255.128
78
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
128.16.32.13
255.255.255.252
153.50.6.27
255.255.255.128
79
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
/21
128.16.32.13
255.255.255.252
153.50.6.27
255.255.255.128
80
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
/21
15.16.192.0
128.16.32.13
255.255.255.252
153.50.6.27
255.255.255.128
81
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
/21
15.16.199.255
15.16.192.0
128.16.32.13
255.255.255.252
153.50.6.27
255.255.255.128
82
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
/21
15.16.199.255
15.16.192.0
128.16.32.13
255.255.255.252
/30
153.50.6.27
255.255.255.128
83
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
/21
15.16.199.255
15.16.192.0
128.16.32.13
255.255.255.252
/30
128.16.32.12
153.50.6.27
255.255.255.128
84
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
/21
15.16.199.255
15.16.192.0
128.16.32.13
255.255.255.252
/30
128.16.32.15
128.16.32.12
153.50.6.27
255.255.255.128
85
Written Exercise Broadcast Addresses
Address
CIDR
Subnet
Broadcast
Subnet Mask
201.222.10.60
255.255.255.248
/29
201.222.10.63
201.222.10.56
15.16.193.6
255.255.248.0
/21
15.16.199.255
15.16.192.0
128.16.32.13
255.255.255.252
/30
128.16.32.15
128.16.32.12
153.50.6.27
255.255.255.128
/25
86
Written Exercise Broadcast Addresses
87
Written Exercise Broadcast Addresses
88
4. IP Routing
89
IP Routing Learns Destinations

• Static routes
• Default routes
• Dynamic routing

90
Static Route Configuration
Router (config)
ip route network mask address interface
distance

• Defines a path to an IP destinationnetwork or
  subnet

91
Dynamic Routing Operations
Routing Protocol
Routing Protocol
A router passes routing information to its
neighbors
Routing Table
Routing Table

• Routing protocol maintains and distributes
  routing information

92
IP Routing Table
Internet
Network 10.1.2.0
Network 10.1.1.0
Network 10.8.4.0
S0
TokenRing
E0
To0
Routing Table
Distance
Network
Interface/NextHop
10.1.2.0/24
0
E0, Directly Connected
10.1.2.4
10.1.1.0/24
0
To0,Directly Connected
Network 10.1.3.0
10.8.4.0/24
S0, Directly Connected
0
10.1.3.0/24
10.1.2.4, NextHop
1
0.0.0.0/0
S0, NextHop
12
Default route
93
Static Routing Configuration
Router(config)
interface E0 ip address 10.1.2.1
255.255.255.0 interface S0 ip address
10.8.4.2 255.255.255.0 interface To0 ip
address 10.1.1.3 255.255.255.0 ip route 10.1.3.0
255.255.255.0 10.1.2.4 1 ip route 0.0.0.0
0.0.0.0 S0 12
94
Routing Table in Windows 98
C\WINDOWSgtroute print Active Routes Network
Address Netmask Gateway Address
Interface Metric 0.0.0.0
0.0.0.0 159.148.108.254 159.148.108.217
1 0.0.0.0 0.0.0.0
193.219.192.226 193.219.192.227 1
127.0.0.0 255.0.0.0 127.0.0.1
127.0.0.1 1 159.148.108.128
255.255.255.128 159.148.108.217 159.148.108.217
1 159.148.108.217 255.255.255.255
127.0.0.1 127.0.0.1 1
159.148.255.255 255.255.255.255 159.148.108.217
159.148.108.217 1 193.219.192.224
255.255.255.248 193.219.192.227 193.219.192.227
1 193.219.192.227 255.255.255.255
127.0.0.1 127.0.0.1 1
224.0.0.0 224.0.0.0 193.219.192.227
193.219.192.227 1 224.0.0.0
224.0.0.0 159.148.108.217 159.148.108.217
1 255.255.255.255 255.255.255.255
193.219.192.227 0.0.0.0
1 C\WINDOWSgt
95
Address Resolution Protocol
I need the Ethernet address of 176.16.3.2.
172.16.3.1
172.16.3.2
IP 172.16.3.2 ???

• Map IP Ethernet

96
Address Resolution Protocol
I need the Ethernet address of 176.16.3.2.
172.16.3.1
172.16.3.2
IP 172.16.3.2 ???

• Map IP Ethernet

97
Address Resolution Protocol
I need the Ethernet address of 176.16.3.2.
172.16.3.1
172.16.3.2
IP 172.16.3.2 ???
IP 172.16.3.2 Ethernet 0800.0020.1111

• Map IP Ethernet

98
Address Resolution Protocol
I need the Ethernet address of 176.16.3.2.
172.16.3.1
172.16.3.2
IP 172.16.3.2 ???
IP 172.16.3.2 Ethernet 0800.0020.1111

• Map IP Ethernet

99
ARP Table Example
100
Ethernet ARP Message Format
101
Excersise / Assignment 1
102
IP Addressing Example
Internet
103
IP Addressing Routing Assignment 1
Internet
A
C
B

• Divide class C address 201.7.8.0 in three
  subnets with subnet mask 255.255.255.224
• Assign IP addresses to all interfaces
• Design routing tables for A, B, C