Skip to main content

IP Fragmentation for Dummy like Me!

Recently I encounter this question, and for some reason I answer it wrong 😓

 I answer "d", which if my boss saw me he would just slap me or something, hahahaha.

So what is the right answer? Lets explore IP Fragmentation and seek the truth.

In short. IP Fragmentation means in situation of where before transmission, when the IP packet is too large, larger than the Maximum Transmission Unit (MTU) of an interface, it shall be fragmented (split) or discarded, depends on situation.

There are situation where fragmentation will occur. We will explore these 2 situation.

1 - Fragmentation at Router.

  • During Packet transmission, PC will ask the router what is the MTU.
  • It will later split the packet into several fragments. Those fragments will hold an identifier in the header. It will later reassembled by receiver into an original PDU (Protocol data unit, contains Packet Header and Packet Payload).
  • This has disadvantage over the router where it will make router to work more just to split packets.
  • Router that receive this long packet will create new packet by copying the header. The data section however is divided in potions on a 8 byte boundary. Also the router will include Fragment Offset, or more-fragment flag (MF) in the header noting the packet sequence of the split fragments.
  • The major problem is if multiple hop have smaller and smaller MTU, the packet is keep being fragmented, adding more work to router.

2 - Fragmentation at Sender
  •  Using Path MTU Discovery (PMTUD), Sender already probe using ICMP indicating the MTU size of the next hop. 
  • IP Packet created is later following the MTU so the router did not have to do extra job re-splitting and repackage back the Packet before transmitting again.
  • This is the recommended method used in the Internet. 
From above explanation, you should know what is the correct answer already!
Psst, it is "b" 😛

Also, you should able to answer the next question here:



Popular posts from this blog

The 7 Deadly Diseases by Dr. William Edward Deming.

 Good advice to follow when it come to product development. I found this here: The diseases are: Lack of constancy of purpose : You must remain focused on doing the right things because they are the right things to do for your customer and to achieve quality. ITSM is not a fad it is a way of behaving. Emphasis on short-term profits : Cutting costs can bring short-term profits and are easy to achieve. But cutting costs can only go on for so long, before you have cut to the bone and have nothing left to cut. Evaluation by performance, merit rating, or annual review of performance : Management by objectives ends up focusing on the objectives and not on the management. It is about “hitting the numbers” and not improvement. Mobility of management : When management changes jobs constantly there is no continuity or constancy of purpose. Each time a new leader comes in, the efforts of quality

Training that I intend to attend and complete by 2020

 #Update: I failed to attend all because depression during lockdown. Will slowly try to do one in 2021.    As mentioned, I want to do these:   This is my checklist, we'll see if I can do it. Finger-crossed.

Memilih Kamera Pertama Anda. Bahagian 2 Tambahan - Kamera Point and Shoot

Edisi Khas untuk kamera Point and Shoot. Penulis merasakan kamera jenis ini tidak mendapat perhatian yang baik dengan ciri yang kompak, ringan dan mudah dibawa. Kebanyakan keluaran lewat 2015 mempunyai spesifikasi yang bagus, setara dengan DSLR dan Mirrorless. Contoh Kamera Point and Shoot keluaran Sony yang terkini bernama Sony ZV-1 Saiz Sensor - Kebanyakan kamera sebegini sensor sebesar 1 inci sehingga APS-C.  Megapixel - Normalnya bermula 12 MP sehingga 26 MP. Hasil gambar juga baik, cuma kekurangan fungsi Penstabil (Stabiliser) menyebabkan kualiti gambar adalah bergantung kepada tetapan (setting) yang betul serta tangan pengambil gambar yang teguh. Saiz Kamera - Kerana saiz yang kompak, ia senang dibawa kemana-mana sahaja, tanpa memakan ruang pada beg mahupun poket. Saiz kecil juga nampak natural, tidak seakan menceroboh momen dengan saiz yang besar, membuatkan orang berasa tidak senang duduk. Versatil - Mempunyai kebolehan merakam video, jadi