TCP/IP and the OSI Model

Transcription

1 TCP/IP BASICS

2 TCP/IP and the OSI Model

3

4 TCP/IP BASICS The network protocol of the Internet Composed of six main protocols IP Internet Protocol UDP User Datagram Protocol TCP Transmission Control Protocol ARP Address Resolution Protocol ICMP Internet Control Message Protocol IGMP Internet Group Message Protocol

5 Internet Protocol Works at layer 3 of the OSI model Responsible for routing packets to the correct destination Allows interconnecting large numbers of sub networks Every device must have a unique IP address

6 User Datagram Protocol Connectionless Does not guarantee delivery Does not maintain packet sequence Implements ports for multiplexing information between applications Provides for a checksum value for data integrity

7 Transmission Control Protocol Connection based Guarantees delivery Maintain packet sequence Implements ports for multiplexing information between applications Provides for a checksum value for data integrity

8 Address Resolution Protocol Used to resolve an IP address to an Ethernet (MAC) address Only used for outgoing packets Resolved addresses are stored in the ARP table Remember that the MAC address is set at the factory. The IP address is set by the network administrator

9 Internet Control Message Protocol Used to pass control information between two computers or routers Used by the ping command Used to report routing problems

10 Internet Group Message Protocol Controls multicast broadcasts Used to tell routers to pass a multicast IP address

11 IP Addresses A unique 32 bit number that identifies the device on the IP network Assigned by the network administrator IP addresses are controlled by Internet Assigned Numbers Authority (IANA) Are allocated in blocks

12 IP Addresses IP addresses are represented in dotted decimal notation Each is number is called an octet An octet is between 0 and 255 (8 bits) An IP address if made up of 4 octets Sample IP addresses

13 IP Addresses Dotted Decimal Binary Hex 0A Dotted Hex 0A

14 IP Addresses Dotted Decimal Binary Hex 7F Dotted Hex 7F

15 IP Addresses Dotted Decimal Binary Hex AC100DFE Dotted Hex AC.10.0D.FE

16 IP Addresses Dotted Decimal Binary Hex C0A80172 Dotted Hex C0.A

17 IP Networks IP networks are groups of IP addresses IP networks are assigned based on class type Referred to as networks or nets Computers on the same network are local Computers on different networks are remote

18 IP Address Classes There are 5 IP address class types CLASS A CLASS B CLASS C CLASS D CLASS E

19 Class A Used for large sized networks Provides IP addresses for up to devices The first number of the dotted quad address is from 1 to 126 The first bit of the binary address is 0

20 Class B Used for medium sized networks Provides IP addresses for up to devices The first number of the dotted quad address is from 128 to 191 The first two bits of the binary address are 10

21 Class C Used for small sized networks Provides IP addresses for up to 254 devices The first number of the dotted quad address is from 192 to 223 The first three bits of the binary address are 110

22 Class D Used for multicast (see RFC 1112) Designed to be used by large numbers of receiving devices The first number of the dotted quad address is from 224 to 239 The first four bits of the binary address are refers to all connect IP devices on the directly connected network

23 Class E Reserved for future addressing modes The first number of the dotted quad address is from 240 to 254 The first four bits of the binary address are 1111

24 The Netmask The Netmask is used to define the local network It is a 32 bit binary number like the IP address It defines the network portion of an IP address

25 The Netmask The standard netmasks Class A Class B Class C

26 IP Address Parts The IP address is composed of two logical parts Network portion Host portion

27 IP - Network Portion The network portion is determined by the netmask Every position where the netmask is a one, the corresponding bit in the IP address is part of the network portion

28 IP - Host Portion The host portion is also determined by the netmask Every position where the netmask is a zero, the corresponding bit in the IP address is part of the host portion

29 IP Address Samples Sample IP addresses and netmasks IP Address Netmask

30 IP Address Address in binary Netmask in binary Network Portion Host Portion

31 IP Address Address in binary Netmask in binary Network Portion Host Portion

32 IP Address Address in binary Netmask in binary Network Portion Host Portion

33 IP Address Address in binary Netmask in binary Network Portion Host Portion

34 Network Number The network number is the network portion of the IP address combined with a host portion of all zeros

35 IP Network Defined Every host on a local IP network must have the same network number Any destination address that does not have the same network number is remote To communicate with a remote host, a gateway (router) must be used