3 het ip-protocol. 3 ip-protocol services routing multiple client protocols datagram delivery...
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3
Het IP-Protocol
3
IP-protocol Services
Routing
Multiple client protocols
Datagram delivery
Independant from the Network Interface Layer
Fragmentation and reassembly
Extensible through IP options
Packet switching technology
3
IP Header
20 bytes
4-bitversion
4-bit hea-der length
8-bit type of service(TOS)
16-bit total length (in bytes)
16-bit identification3-bitflag 13-bit fragment offset
8-bit time to live (TTL)
8-bit protocol 16-bit header checksum
32-bit source IP address
32-bit destination IP address
Options (if any)
data
0 15 16 31
3
Wat is een IP Address?
133.120.75.8
86
131.107.0.0131.107.0.0
131.107.3.27
133.120.0.0133.120.0.0
129.102.12.7
129.102.0.0
129.102.16.2
90
94
MARIA AVEMARIA AVE
3
Conversie IP Adres van Binair naar Decimaal Formaat
11 11 11 11 11 11 11 11
128128 6464 3232 1616 88 44 22 11
8 Bits
255 Decimal Value
3
Netwerk ID en Host ID
Network ID Host ID
32 Bits
w. x. y. z.
131.107.3.24Example:
Class B
3
Address Classes
Class C
w x y z
Class ANetwork
IDHost ID
0
Class BNetwork ID Host ID
1 0
Network ID Host ID
1 1 0
Numberof Networks
126
16,384
2,097,152
Number of Hosts
per Network
16,777,214
65,534
254
3
Address Class Summary
NumberNumberof Networksof Networks
NumberNumberof Networksof Networks
126126
16,38416,384
2,097,1522,097,152
Number of HostsNumber of Hostsper Networkper Network
Number of HostsNumber of Hostsper Networkper Network
16,777,21416,777,214
65,53465,534
254254
Class AClass AClass AClass A
Class BClass BClass BClass B
Class CClass CClass CClass C
Range ofRange ofNetwork IDs Network IDs (First Octet)(First Octet)
Range ofRange ofNetwork IDs Network IDs (First Octet)(First Octet)
1 – 1261 – 126
128 – 191128 – 191
192 – 223192 – 223
3
Assigning Network IDs
Router
AA CC BB
124.x.y.z124.x.y.z 192.121.73.z192.121.73.z 131.107.y.z131.107.y.z
Router
3
Network Addressing Guidelines
Network ID Must Be Unique
127 Is Reserved for Diagnostic Loopback Functions
Network ID Cannot Be all 255 (All Bits Set to 1)
255 is a broadcast address
Network ID Cannot Be all 0 (All Bits Set to 0)
0 indicates a local network
3
Assigning Host IDs
Router Router
124.0.0.27124.0.0.27
124.0.0.28124.0.0.28
124.0.0.29124.0.0.29
131.107.24.27131.107.24.27
131.107.24.28131.107.24.28
131.107.24.29131.107.24.29
192.121.73.1192.121.73.1
124.0.0.1124.0.0.1 192.121.73.2192.121.73.2
131.107.24.1131.107.24.1
124.x.y.z124.x.y.z 192.121.73.z192.121.73.z 131.107.24.z131.107.24.z
AA CC BB
3
Host Addressing Guidelines
Host ID Must Be Unique to the Network ID
Host ID Cannot Be 255 (All Bits Set to 1)
255 is a broadcast address
Host ID Cannot Be 0 (All Bits Set to 0)
0 means “this network only”
3
Common Addressing Problems
Network IDs on the Local Network Don’t Match
Local hosts cannot communicate
Host IDs on the Local Network Are Duplicate
Windows NT–based hosts cannot initialize
Other TCP/IP-based hosts may not be able to communicate
Other TCP/IP-based hosts could hang
3
How to choose/assign IP-addresses ?
Internet Service Provider
ICANN - Internet Corporation for Assigned Names and Number
RIPE – ARIN – APNIC – LACNIC - AfriNIC
Private Address Space (RFC 1918)
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
3
Loopback interface
127.0.0.1
name localhostIP outputfunction
IP inputfunction
Place on IPinput queue
Loopback driver
Ethernet driver
Dest. IP = broadcast ormulticast ?
Place on IPinput queue
yes
Dest. IP = interfaceaddress ?
noyes
Ethernet
IP driver
3
Exercise
3
Excercise
Connect two pc’s to a hub and assign an ip-address from the same network. Issue a ping command from one to the other. Do the same with ip-addresses from different networks
Find the public address space assigned to your company (or any company that you know)
3
The Domain Name System
An Alias Used to Reference a TCP/IP Host
A Fully Qualified Domain Name (FQDN)
Example: ftp.microsoft.com
Provides a Simplified Way to Access a TCP/IP Host
Used by Ping and Other TCP/IP Utilities
Entries Are Stored in the HOSTS File or DNS
Viewed with the nslookup Utility
3
IP addressing summary
Network part: all host bits 0
193.58.9.0
First ip address :
193.58.9.1
Broadcast address: all host bits 1
193.58.9.255
3
Overview Subnetting
What Is a Subnet?
Subnet Addressing
What Is a Subnet Mask?
Defining a Subnet Mask
Defining Network IDs for an Internetwork
Defining Host IDs for Subnets
3
What Is a Subnet Mask?
Distinguishes the Network ID from the Host ID
Used to Specify Whether the Destination Host is Local or Remote
3
Default Subnet Masks (No Subnetting)
Bits Used for Subnet MaskBits Used for Subnet MaskAddressAddressClassClass
Dotted DecimalDotted DecimalNotationNotation
Dotted DecimalDotted DecimalNotationNotation
Class A
Class B
Class C
Class A
Class B
Class C
11111111 00000000 00000000 00000000
11111111 11111111 00000000 00000000
11111111 11111111 11111111 00000000
11111111 00000000 00000000 00000000
11111111 11111111 00000000 00000000
11111111 11111111 11111111 00000000
255.0.0.0
255.255.0.0
255.255.255.0
255.0.0.0
255.255.0.0
255.255.255.0
Class B ExampleClass B Example
16.200131.107.
0.0255.255.
131.107.
w.x.
IP Address
Subnet Mask
Network ID
Host ID 16.200
y.z
3
10011111 11100000 00000111 10000001
11111111 11111111 00000000 00000000
10011111 11100000 00000111 10000001
11111111 11111111 00000000 00000000
10011111 11100000 00000000 0000000010011111 11100000 00000000 00000000
IP Address
Subnet Mask
IP Address
Subnet Mask
ResultResult
How IP Determines If a Packet Is Destined Locally or Remotely
Local IP and Destination IP are ANDed with Mask 1 AND 1 = 1 Other combinations = 0
If ANDed results of source and destination hosts match, the destination is local
3
Problem : Waste of address space !
Inefficient use of address space
193.107.8.z193.107.8.z
193.107.16.z193.107.16.z
193.107.24.z193.107.24.z
193.107.8.1193.107.8.1 193.107.16.2193.107.16.2 193.107.16.1193.107.16.1 193.107.24.1193.107.24.1
A BWe only use 2 address out of
254
We only use 2 address out of
254
3
How is subnetting done?131.107.3.27131.107.3.27
Subnet 1Subnet 1131.107.131.107.1010.0.0
255.255.255.255.255255.0.0
Subnet 1Subnet 1131.107.131.107.1010.0.0
255.255.255.255.255255.0.0
131.107.10.12131.107.10.12
Subnet 2Subnet 2131.107.131.107.33.0.0
255.255.255.255.255255.0.0
Subnet 2Subnet 2131.107.131.107.33.0.0
255.255.255.255.255255.0.0
131.107.12.7131.107.12.7
131.107.12.0
131.107.12.31131.107.12.31
Main Network
Borrow bits from host part
All hosts on same segment have same subnet number
Subnet 3Subnet 3131.107.131.107.1212.0.0
255.255.255.255.255.255.00
Subnet 3Subnet 3131.107.131.107.1212.0.0
255.255.255.255.255.255.00
3
Examples of a Custom Subnet Mask (Subnetting)
Bits Used for Subnet MaskBits Used for Subnet MaskAddressAddressClassClass
Dotted DecimalDotted DecimalNotationNotation
Dotted DecimalDotted DecimalNotationNotation
Class ?
Class ?
Class ?
Class ?
11111111 11111111 00000000 00000000 11111111 11110000 00000000 00000000
11111111 11111111 11111111 0000000011111111 11111111 11110000 00000000
11111111 11111111 00000000 00000000 11111111 11110000 00000000 00000000
11111111 11111111 11111111 0000000011111111 11111111 11110000 00000000
255.255.0.0255.240.0.0
255.255.255.0255.255.240.0
255.255.0.0255.240.0.0
255.255.255.0255.255.240.0
Class B ExampleClass B Example
131.107.16.
255.255.255.
131.107.
w.x.
IP Address
Subnet Mask
Network ID
Subnet ID
Host ID w.x.y.
200
0
y.z
16.
200
z
3
IP Addresses
131.107.35.200131.107.61.26
Subnet Mask
Using the Subnet Mask to Determine If a Host Is Local or Remote
Comparing Two Network IDs Does Not Always Indicate a Local or Remote Host
Example 1
153.170.37.16217.170.172.233
Example 2
131.107.35.200131.107.61.26
Compare Both Addresses to a Subnet Mask to Determine Location
255.255.0.0, or255.255.255.0
Same Network?
YesNo
3
Determining the Number of Subnet Mask Bits
Class BNetwork ID Host ID
1
SubnetMask
Number of Subnets
0
2 . . . 254
Number of Hosts
Subnet Mask
Host ID
16,382 . . . . . . 254
3
Defining a Subnet Mask
Determine the Number of Subnets
Convert the Number of Subnets to Binary
Convert the Required Number of Bits to Decimal (High Order)
11
22
33
Example of Class B Address
Number of SubnetsNumber of Subnets
Binary ValueBinary Value
Convert to DecimalConvert to Decimal
6
0 0 0 0 0 1 1 0
= 6
(3 Bits)
4+2
255 . 255 . 224 . 011111111 11111111 11100000 00000000
3
3
Shortcut to Defining Network IDs
List the Number of Bits (High Order) Used for Subnet Mask
Convert the Bit with the Lowest Value to Decimal
Increment the Value for Each Bit Combination
1110000011100000
3232
w.x.32.1 w.x.63.254
w.x.64.1 w.x.95.254
11
22
330+ 32= 32+ 32= 64+ 32= 96 + 32= 128+ 32= 160
w.x.96.1 w.x.127.254
w.x.128.1 w.x.159.254
w.x.160.1 w.x.192.254
3
Defining Host IDs for a Subnet
Subnet IDsSubnet IDs Host ID RangeHost ID Range
“Invalid”x.y.32.1 – x.y.63.254x.y.64.1 – x.y.95.254x.y.96.1 – x.y.127.254x.y.128.1 – x.y.159.254x.y.160.1 – x.y.191.254x.y.192.1 – x.y.223.254“Invalid”
“Invalid”x.y.32.1 – x.y.63.254x.y.64.1 – x.y.95.254x.y.96.1 – x.y.127.254x.y.128.1 – x.y.159.254x.y.160.1 – x.y.191.254x.y.192.1 – x.y.223.254“Invalid”
00000000 = 000100000 = 3201000000 = 6401100000 = 9610000000 = 12810100000 = 16011000000 = 19211100000 = 224
00000000 = 000100000 = 3201000000 = 6401100000 = 9610000000 = 12810100000 = 16011000000 = 19211100000 = 224
Each Subnet ID Indicates the Beginning Value in a Range
The Ending Value Is One Less Than the Beginning Value of the Next Subnet ID
3
Subnet Addressing
Determine the Number of Required Network IDs
One for each subnet
One for each wide area network connection
Determine the Number of Required Host IDs per Subnet
One for each TCP/IP host
One for each router interface
Define One Subnet Mask Based on Requirements
Define a Unique Network ID for Each Subnet Based on the Subnet Mask
Define Valid Host IDs for Each Subnet Based on the Network ID
3
Exercise: Subnetting
3
Example : Assign subnets
210.10.10.0/24
10
10
10
3
Excercise : Assign subnets (subnet zero is valid)
TokenRing
Internet
TokenRing
100100
100
193.58.2.0 / 24
28
505050
10
40
193.58.1.0 /24
6
193.58.3.0 / 24
2 2
40
3
Solution
Network #bits Mask #hosts First Last Broadcast
193.58.9.0 24 255.255.255.0 254 193.58.9.1 193.58.9.254 193.58.9.255
193.58.9.0 25 255.255.255.128 126 193.58.9.1 193.58.9.126 193.58.9.127
193.58.9.128 25 255.255.255.128 126 193.58.9.129 193.58.9.254 193.58.9.255
100100
193.58.2.0 / 24193.58.1.0 /24
193.58.3.0 / 24
11111111 11111111 11111111 10000000
255 . 255 . 255 . 128
3
Excercise : Assign subnets (subnet zero is valid)
TokenRing
Internet
TokenRing
193.58.1.0 /25
193.58.1.128 /25
193.58.2.0 /25
193.58.2.0 / 24
193.58.3.192 / 27
193.58.3.0 / 26
193.58.2.192 /26
193.58.2.128 /26
193.58.3.224 / 28
193.58.3.64 / 26
193.58.1.0 /24
193.58.3.240 / 29
193.58.3.0 / 24
193.58.3.248 / 30
193.58.3.252 / 30
193.58.3.128 / 26
3
50
Internet
192.168.1.0 / 24
10
2030
40
Excercise : Assign subnets (subnet zero is valid)
3
Exercise
25.158.7.89/19
Define network mask
Define network
Define first ip address
Define last ip address
Define broadcast address
3
Review
What Is a Subnet?
Subnet Addressing
What Is a Subnet Mask?
Defining a Subnet Mask
Defining Network IDs for an Internetwork
Defining Host IDs for Subnets
3
Commands netstat
Network connections and routing table Unix - Windows NT
ifconfig
interface information Unix
winipcfg
Windows 95/98 ipconfig
Windows NT/2000
3
Classless Interdomain Routing (CIDR)
Exhaustion IP address space
No class A - B and C
w.x.y.z/s with 1 <= s < = 32
Route aggregation
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