1 ip: internet protocol addresses. 2 internet protocol (ip) only protocol at layer 3 fundamental in...
TRANSCRIPT
![Page 1: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/1.jpg)
1
IP: Internet Protocol Addresses
![Page 2: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/2.jpg)
2
Internet Protocol (IP)
• Only protocol at Layer 3
• Fundamental in suite
• Defines– Internet addressing– Internet packet format– Internet routing
![Page 3: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/3.jpg)
3
IP Addressing
• Abstraction
• Independent of hardware addressing
• Used by– Higher-layer protocols– Applications
![Page 4: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/4.jpg)
4
IP Address
• Virtual– Only understood by software
• Used for all communication
• 32-bit integer
• Unique value for each host
![Page 5: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/5.jpg)
5
IP Address Assignment
• An IP address does not identify a specific computer. Instead, each IP address identifies a connection between a computer and a network. A computer with multiple network connections (e.g., a router) must be assigned one IP address for each connection.
![Page 6: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/6.jpg)
6
IP Address Details
• Divided into two parts– Prefix identifies network– Suffix identifies host
• Global authority assigns unique prefix to network
• Local administrator assigns unique suffix to host
![Page 7: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/7.jpg)
7
Original Classes Of Addresses
• Initial bits determine class
• Class determines boundary between prefix and suffix
![Page 8: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/8.jpg)
8
Dotted Decimal Notation
• Shorthand for IP address
• Allows humans to avoid binary
• Represents each octet in decimal separated by dots
• NOT the same as names like www.somewhere.com
![Page 9: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/9.jpg)
9
Computing the Class of an Address
![Page 10: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/10.jpg)
10
Example Of Dotted Decimal Notation
• Four decimal values per 32-bit address• Each decimal number
– Represents eight bits– Is between 0 and 255
![Page 11: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/11.jpg)
11
Classful Addresses And Network Sizes
• Maximum network size determined by class of address• Class A large• Class B medium• Class C small
![Page 12: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/12.jpg)
12
Division of the Address Space
![Page 13: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/13.jpg)
13
Addressing Example
![Page 14: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/14.jpg)
14
Illustration Of Router Addresses
• Address prefix identifies network• Need one router address per connection
![Page 15: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/15.jpg)
15
Special Addresses
• Network address not used in packets• Loopback never leaves local computer
![Page 16: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/16.jpg)
16
Subnet And Classless Addressing
• Not part of original scheme
• Invented to prevent address exhaustion
• Allow boundary between prefix and suffix to occur on arbitrary bit boundary
• Require auxiliary information to identify boundary
![Page 17: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/17.jpg)
17
Address Mask
• Accompanies IP address
• 32 bit binary value
• Specifies prefix / suffix boundary– 1 bits cover prefix– 0 bits cover suffix
• Example: class B mask is 255.255.0.0
![Page 18: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/18.jpg)
18
Subnet Addressing
• Goal: extend address space
• Invented in 1980s
• Works within a site
• Technique– Assign single network prefix to site– Divide suffix into two parts: network at site and
host
• Typical use: divide class B address
![Page 19: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/19.jpg)
19
Example Of Subnet Addressing
• Single Class B number such as 128.10.0.0 assigned to site
• Site chooses subnet boundary such as 24 bits
• Routers and hosts configured with corresponding subnet mask M = 255.255.255.0
• Given destination address, D, extract prefix with ‘‘logical and’’ operation D & M
![Page 20: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/20.jpg)
20
Classless Addressing
• Goal: extend address space
• Invented in 1990s
• Works throughout Internet
• Accommodates– Original classful addresses– Subnet addresses– Other forms
![Page 21: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/21.jpg)
21
Classless Addressing (continued)
• Technique– Allow arbitrary prefix size– Represent network address as pair
(address, mask_size )
• Known as Classless Inter-Domain Routing (CIDR)
![Page 22: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/22.jpg)
22
CIDR
• Uses slash notation
• Example128.211.0.0/17
means that the boundary between prefix and suffix occurs after the first 17 bits.
• Each network can be as large or small as needed (power of two)
![Page 23: 1 IP: Internet Protocol Addresses. 2 Internet Protocol (IP) Only protocol at Layer 3 Fundamental in suite Defines –Internet addressing –Internet packet](https://reader035.vdocuments.site/reader035/viewer/2022062304/56649d135503460f949e6ed4/html5/thumbnails/23.jpg)
23
Illustration of CIDR addressing for a /28 prefix