IPV4 Header format | TTL | Protocol | Header checksum | Options

prerequisite video link : -
https://youtu.be/wqt4BSMKw5s

https://youtu.be/zHXmarHg1YM
TTL :- Time to live field is an 8 bits field. it is used for reducing the network traffic when some datagram fall in a loop of routs and router just forwards the same datagram again and again.
So The time-to-live (TTL) is the number of hops that a packet is permitted to travel before being discarded by a router.
Protocol : - Protocol field is used to indicate that which protocol this datagram is going to.
Generally the numbers are assigned for protocols such as 6 for TCP, 17 for UDP, 1 for ICMP
Header Checksum : - this 16 bits field is used for error control. error control in IP protocol is just for header not for entire data.
the header size keep changing at every routers so checksum is calculated at each routers.
if data is to be included for checksum then the routers will have to do lots of computation.
Options : - this is used for padding, record route, source route etc. And used by network administrator to check if a path is working or not

Видео IPV4 Header format | TTL | Protocol | Header checksum | Options канала Rishi Yadav