IP DATAGRAM HEADER FORMAT:

 It is given in the figure below:

In the table:

• VERS denotes the version of IP.
• H.LEN denotes the header length in units of 32-bits.
• SERVICE TYPE denotes sender's preference for low latency, high reliability that is rarely needed.
• TOTAL LENGTH denotes total octets in datagram.
• IDENT, FLAGS, FRAGMENT OFFSET denotes the values used with fragmentation.
• TTL denotes time to live decremented in each router; datagram discarded when TTL = 0.
• TYPE denotes type of protocol carried in table e.g., TCP, UDP.
• HEADER CHECKSUM denotes 1's complement of 1's complement sum.

SOURCE DIST IP ADDRESS denotes IP addresses of original source and ultimate