Solved

# Question on IP Datagram

Posted on 2002-03-14
550 Views
Can somebody please tell me this:

If a datagram contains one 8-bit option and one 8-bit data value, what values will be found in the header fields H.LEN and TOTAL LENGTH?
0
Question by:ani1

LVL 16

Accepted Solution

SteveJ earned 15 total points

As an EXAMPLE, an IP datagram within an 82 byte ethernet frame would breakdown as follows.

Total frame size - 82 bytes
IP length - 68 bytes

So the frame is made of of 68 bytes of IP stuff, 20 bytes of which is header, and 14 bytes of ethernet stuff.

Good luck.
Steve

0

Author Comment

Thanks Steve.
Though it exactly did not give me the answer, it gave an idea of how to proceed.

Thanks.
0

LVL 3

Expert Comment

Hi,

first of all 20 bytes is the minimum for the IP header, so if you have a 8 bit option header length of the IP datagram will be 28 bytes. Total length of the IP datagram (packet, datagram->UDP packet)will be 28 + 8=36 bytes. However if we talk about Ethernet, as the minimum length of a packet must be 64 bytes, some padding bytes will be added to this packet after the Ethernet packet is added.

regards...
0

LVL 3

Expert Comment

Also I would like to add that the dimension of the header lenth in the IP packets is 32 bits so the options that are shorter than 32 bits are padded to 32 bits long. And with an option of 8 bits you will have a header length value of (20 + 4(4 instead of 1))*8bits/32bits=6.

cincin
0

LVL 79

Expert Comment

No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area for this question:

I recommend: points to SteveJ

if there is any objection or other expert commentary to this recommendation then please post in here within 7 days.

thanks,
lrmoore
EE Cleanup Volunteer
---------------------
0

LVL 1

Expert Comment

Comment from expert accepted as answer

Computer101
0

## Featured Post

Lets look at the default installation and configuration of FreeProxy 4.10 REQUIREMENTS 1. FreeProxy 4.10 Application - Can be downloaded here (http://www.handcraftedsoftware.org/index.php?page=download) 2. Ensure that you disable the windows fi…
ADCs have gained traction within the last decade, largely due to increased demand for legacy load balancing appliances to handle more advanced application delivery requirements and improve application performance.
Viewers will learn how to connect to a wireless network using the network security key. They will also learn how to access the IP address and DNS server for connections that must be done manually. After setting up a router, find the network security…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…