Ace Test Series: Computer Networks - Ipv4

Question

Why is it 416 ?

Answer 1

Mtu is 440

Ip header =20

So 420 bytes still there for data

Amount of data in fragment should be divisible by 8

420 not divisible by 8 so we take 416

Answer 2

MTU is given as 440 ,so data that can be sent in each fragment is 440 - 20 = 420 . but 420/8 is not a whole number so we will take other least multiple just lesser than 420 which comes to be 416 . the fragments will be
fragment size                        offset
416                                           0
416                                          52
416                                           104
219                                         156

Answer 3

Ans should be 165,

mtu=440(given),(which is divisible by 8)

Ip packet containing 1500 byte data,so 1480(payload)+20(IP header)

420+20

420+20

420+20

220+20,

So last frame offset is  1320/8=165

Comments

wrong approach!! in mtu also there has to be 20 byte header