IPv4 | Internet Protocol version 4 | TechTerms

Understand IPv4 or interner protocol verison 4 datagram header format. All fields explained in detail with examples containing version number, header length, DSCP, datagram length,Identifier, flags, fragmentation offset, time to live, protocol, header checksum, source and destination IP address, and Options. Data or payload contains the transport layer segment.

Version number specifies the version of datagram - version 4 or version 6. The header length tells the total length of the IPv4 datagram header. The 'OPTION’ field is variable in length and is rarely used. DSCP classify IP packets. Datagram length tells the total length of the IP datagram. Identifier, flags, and fragmentation offset are used in case of IP fragmentation. Time-to-live field is used to limit the lifetime of an IP datagram. Protocol indicates to which transport layer protocol the data portion of the IP datagram should be passed. Header checksum helps in detecting the bit errors in the received IP datagram’s header. Source and destination IP address represents the IPv4 address of the source host and the destination host, respectively. Data (Payload) contains the segment of the transport layer.

[Aryanverma-cvwq]

Sir please dont stop uploading, your videos are very helpful and we are vey grateful to have a wonderful teacher like you whose concepts are crisp clear sharing his knowledge with us

[williamdekou]

Amazing content! Worth 5 years of Engineering

[safarnama]

Learnt something ? ...Very less people are born with such talent sir . You way of explaining should take you to next level .

[rubansn]

at the end, "if u learnt something from this..." oh man, we learnt a lot. Thanku for this effort

[wsGadDaddy]

i couldn't be happier, best explanation i have ever met

[HariKrishna-mwrr]

Sir ..You are taking huge time to upload

[mdchowdhury]

You're the best. I was looking for your video to understand IP Header. Thanks for teaching us and lots of respects.

[mdataul]

I don't understand this concept so sir you explain very simple i am also learning about this topic so let me full ip ADDRESSING concept clear upload more video in this topic

[Sumit-ccfw]

I just don't have words for your crystal clear explanation, you have done a fantastic job.

[Rain_MG]

your explanation of fragmentation is confusing, as you divide by 8 each time, however you should divide the length by 8 only if it was provided to bit, since all we're doing here is converting to bytes
it would be better to divide the whole length by 8 once and then use that to offset regularly (the offset would be where the last fragment was cut)
and if the length was given in bytes then don't divide by 8
You present it as just the method to do offsets
otherwise, great video, really helpful, thanks a lot

[ilavarasib]

very good content sir. learnt a lot. please do videos on TCP, UDP and MAC header structure and its explanation sir.

[ishaaq]

Awesome..With animated..looking moreee from u💯💯💯💯

[sokiynanaser]

Amazing !!!!you just explained everything

[ciscobatais]

excellent explanation keep it up (high thumb)

[jjjjson]

There are two parts I do not understand well so can someone please explain in more detail:
1) At 2:25 the lecturer said if "the value in the header length field is 5, it refers that the length of IPv4 header is 5 words. One word in IPv4 is 4-byte in length. Therefore the total length of the IPv4 header will be 5 x 4 = 20-bytes." I'm not sure what is meant by "word" and how he came up with the length of 5 words to begin with, instead of say, 2 words or 3 words.

2) At 4:38 the lecturer calculated the theoretical length of IP datagram using datagram length of 16-bit: 2^16-1=65535 bytes. How come this calculation is different from calculating the total length of IPv4 datagram header using header length of 4-bit from earlier in the video (where the maximum header length was 2^4 -1=15, then 15 x 4 = 60 bytes max)? Doesn't the IP datagram length calculation need to take that 65535 and multiply by 4 as well? I feel like I am misunderstanding something along the way.

[sudhakarbala]

Awesome explanation.. please do video for ipv6 also

[proteanguy]

Congratulations for 100k subs buddy and upload tcp and udp Asap 😃

[gosaitsentsima]

Thank you for the video, Kindly share the link for the notes, need to expand brain further

[moyura]

@ 6:37 Shouldn't the do not fragment IP datagram D:1 always set M bit to 0 ?

[arugarg]

Orr videos kro upload. That's helpful man....