Hi All CCIE'S and cisco champions...
It's a basic question about IP but i don't know it and i am eager to know it..........Please help me out.....
I have some data to share with you and then i have some confusions that i like to ask.
I captured the packets through ethreal...
Here is the output
Version : 4
Header : 20 Bytes
I was reading a document where it says.. Header length in 32 bit words, so if the number is 5 then 5*32/8=20 Bytes and the maximum size is 15*32 bit...
What is the bit words and how we wee these bit words and say whether its a t number or 10 or 15....
Type of service:
0*00: Default
ECN : 0*00
.... ..0. : ECN Capable Transport
.... ...0 : ECN-CE:0
As i understand 101 is critical, but all the packets were having the same output, whereas if its a normal packet the value should be something else.
Total Length : No of octets that the ip datagram takes up including the header. The max size that an ip datagram can be is 65,535...
on all the packets it shows 1300
Identification number:
I understand it that i gives a unique numer serially to each packet..e.g 0*5d9a (23962) and 0*5d9b (23963)
Flags:
0*4
.1.. : Dont Fragment-Set
..0.0 : MF:Not Set
???????????
Frag Offset : o in all the packets..
?????????
TTL : 128 in all the packets.
I understand that ttl is a value when we send a packet each router reduce the value to 1 and send the packet to next router, when the packet reaches to destination then this values goes to 0......M i right...
Now i have one cofusion..
I did the ping from my pc..
Latency 5 ms--ttl116
Latency 5 ms--ttl53
Latency 289ms--ttk237
why there is a difference of ttl when both latencies are same.......
and how it decides then which ttl it should take..
Protocol: TCP then it shows 6, icmp it shows 1.
I understand it..
And then source address and destination address..
I understand it.
Now would someone please help me out the clear my doubts.....
Thanks a Ton for all your replies..
