TCP/IP Datagram Explain

 

 

 

********************************************************************************

  Ethernet Transmission Line

  ________________________________________________________________________

 |                 |           |            |                 |           |

 | Ethernet Header | IP Header | TCP Header | Appln Header    | User Data |

 |-----------------+-----------+------------+-----------------------------|

 | 14 Bytes        | 20 Bytes  |  20 Bytes  | variable length             |

 |_________________|___________|____________|_____________________________|

 <-------------------------- Ethernet Frame ------------------------------>

 

################################################################################

  Format of Ethernet Data Frame

  ___________________________________________________________

 |                  |             |            |             |

 | Destination Addr | Source Addr | Frame Type | Frame Data  |

 |------------------+-------------+------------+-------------|

 |  6 Bytes         |  6 Bytes    |  2  Bytes  |             |

 |__________________|_____________|____________|_____________|

 

  If the packet is a valid IP packet then the value of

  Frame type field (13th and 14th bytes) will be 08 0016.

 

 

  

################################################################################

  Format of IP Datagram

 _____  _________________________________________________________________________

  /|   | Version | Header Length | Type of Service| Total Packet Length(2 bytes) |

   |   |(4 Bits) |  (4 Bits)     | (8 Bits )      |          (16 bits)           |

   |   |------------------------------------------+--------------+---------------|

   |   | Identication (2 Bytes)                   | Flags(3 bits)|Fragment Offset|

  20   |------------------------------------------+------------------------------|

 Bytes | Time to Live(1 byte) | Protocol (1 Byte) |  Header Check Sum. (2 Bytes) |

   |   |-------------------------------------------------------------------------|

   |   |                  Source IP Address (4 Bytes)                            |

   |   |-------------------------------------------------------------------------|

  /|   |                  Destination IP Address (4 Bytes)                       |

  -----|-------------------------------------------------------------------------|

       |          Options (if any)   |      Padding ( if Required )              |

       |-------------------------------------------------------------------------|

       |                            Data                                         |

       |_________________________________________________________________________|

 

  

 

################################################################################

  The Common TCP/IP Protocol that use IP

  Prot       Value

  -----------------

  TCP  ---> 06

  UDP  ---> 17

  ICMP ---> 01

  IGMP ---> 02

 

 

  

################################################################################

  Format of TCP Datagram

   _______________________________________________________________

  | Source Port (2 Bytes)         | Destination Port (2 Bytes)    |

  |---------------------------------------------------------------|

  |                    Sequence Number (4 Bytes)                  |

  |---------------------------------------------------------------|

  |                    Acknowledge Number (4 Bytes)               |

  |---------------------------------------------------------------|

  | Hlen   |  Reserverd   | Code Bits |    Window                 |

  |(4 Bits)| (6 Bits )    | (6 Bits ) |    (2 Bytes )             |

  |-----------------------------------+---------------------------|

  |        Checksum (2 Bytes)         |    Urgent Data (2 Bytes)  |

  |---------------------------------------------------------------|

  |        Options (If Any - 3 Bytes )     |  Padding (1 Bytes )  |

  |---------------------------------------------------------------|

  |                          DATA                                 |

  |_______________________________________________________________|