Internet Addresses
- name - specific identification of a machine, user or an application
- address - physical or logical location in a network
- route - how to get a datagram to the address
- name server - resolves the address and route from the name
- The Domain Name Service
NIC maintains a list of network names and corresponding network gateway addresses of top level domains (.arpa, .com, .edu, .gov, .mil, .net, .org)
- Subnetwork Addressing
- Physical Address (Media access control-MAC Address) [Ethernet uses 48 bits] {IEEE has taken over the role of assigning addresses from Xerox}
IP Addresses - assigned by Network Information Center (NIC)
| Class A (0-127) |
| 0 | Network(7 bit) | Local Address(24 bit) |
|
| Class B (128-191) |
| 10 | Network(14 bit) | Local Address(16 bit) |
|
| Class C (192-223) |
| 110 | Network(21 bits) | Local Address(8 bits) |
|
| Class D (224 - 239) |
| 1110 | Multicast Address(28 bits) |
|
Private IP addresses provide a basic form of security. Network connections with computers having privatge IP addresses are not possible from the outside world (Internet).
Private IP address networks are:
| Name |
start IP address |
end IP address |
classful description |
largest CIDR block |
| 24-bit block | 10.0.0.0 | 10.255.255.255 | single class A | 10.0.0.0/8 |
| 20-bit block | 172.16.0.0 | 172.31.255.255 | 16 contiguous class Bs | 172.16.0.0/12 |
| 16-bit block | 192.168.0.0 | 192.168.255.255 | 256 contiguous class Cs | 192.168.0.0/16 |
IPng:IP Version 6
- 128-bit network address instead of 32-bit
- more efficient IP header with extensions for applications and options
- no header checksum
- flow label for QoS requirements
- prevention of intermediate fragmentation of datagrams
- built-in security for authentication and encryption
ex. What kind of address is 192.132.89.65?
Address Resolution Protocols
converts IP addresses to physical addresses using an ARP cache address translation table
| IF Index (Interface - physical port) |
Physical Address |
IP Address |
Type of entry |
