2. Does a destination address in an IP datagram ever refer to an intermediate ro
ID: 3809616 • Letter: 2
Question
2.Does a destination address in an IP datagram ever refer to an intermediate router? Explain.
3.If one captures an IP datagram passing across a network in the middle of the Internet, how many FRAME headers will appear before the datagram?
4.Assume that there is some misconfiguration on two routers in the network. Do datagrams loop around in the network forever? Explain yes or no.
5.Where in a Layer 2 FRAME IP datagram is encapsulated? What value will the frame “type” field have if it is carrying IPv4 packet?
6.If you capture an IP packet, does a MAC address appear anywhere in the IP packet header? Explain yes or no.
7.What is the purpose of IPv4 header checksum?
Additional problems for HW:
An IP datagram has arrived with the following information in the header (in hex). All answers must be in DECIMAL.
45 00 00 54 00 03 00 00 20 06 00 00 7B 4E 03 02 B4 0E 0F 55
Are there any options?
Is the packet fragmented?
What is the size of the payload?
Is a checksum used?
How many more routers can the packet travel to?
What is the identification number of the packet?
What is the type of service?
Calculate the Checksum for the following IPv4 Header.
Note: The values given for each field are in decimal number format. The checksum value must be in HEX.
4
5
0
28
1
0
0
4
17
0
12.101.14.5
10.6.10.240
next-hop forwarding help please.
4
5
0
28
1
0
0
4
17
0
12.101.14.5
10.6.10.240
Explanation / Answer
Assume that there is some misconfiguration on two routers in the network. Do datagrams loop around in the network forever? Explain yes or no.
The answer is NO.
The packet wont loop due to TTL field in IP Header.After each hop a counter will get decreased by 1.When it becomes 0, the packet is discarded and an error message will be send to the server.
Where in a Layer 2 FRAME IP datagram is encapsulated? What value will the frame “type” field have if it is carrying IPv4 packet.
Data is passed to IP typically from one of the two main transport layer protocols either TCP or UDP. This data is already in the form of a TCP or UDP message with TCP or UDP headers. This is then encapsulated into the body of an IP message, usually called an IP datagram or IP packet.
If you capture an IP packet, does a MAC address appear anywhere in the IP packet header? Explain yes or no.
Yes.Every packet is encapsulated inside a frame, containing both a source and destination MAC address.
Both the source and the destination MAC addresses are removed once it crosses out of the local broadcast domain (moves across a router), and are replaced with the appropriate addresses in the next broadcast domain.
In most cases, this means that the MAC will be changed many times along the way.
What is the purpose of IPv4 header checksum?
IPv4 Header checksum is used to protect the header of IPv4 data packets from corrupting.It is 16 bits long and a part of IP Packet Header and calculated for header bytes only.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.