Project 3 Implementing IPv4.

Project 3
Description
In this project, you will be implementing IPv4. I will have a server running that will accept IPv4 packets,
verify the checksum, and reply with (in text) the word “good” if the packet is formatted properly, it can
correctly verify the checksum, and the amount of data sent matches the expected size of the packet.
If the server detects a problem with one of your packets, it will respond with a line of text indicating what
it thinks the problem is. If you receive an indication from the server that a packet was bad, the server will
then close the connection, so don’t try to send any more packets. Instead, restart your program and make
a new connection for future packets.
In the following table, I will tell you whether or not to correctly implement a header field. If I say do not
implement, simply fill that field with all zeros.
Version Implement
HLen Implement
TOS Do not implement
Length Implement
Ident Do not implement
Flags Implement assuming no fragmentation
Offset Do not implement
TTL Implement assuming every packet has a TTL of 50
Protocol Implement assuming TCP for all packets
Checksum Implement
SourceAddr Implement with an IP address of your choice
DestinationAddr Implement using the IP address of the server
Options/Pad Ignore (do not put in header)
Data Implement using zeros or random data
Send the packets as sequences of bytes directly through the socket’s output stream. The host will be the
same as the previous project: codebank.xyz on port 38003.
For more information about the implementation of IPv4, see your textbook, the RFC specification at https:
//tools.ietf.org/html/rfc791, or the Wikipedia article about IPv4: https://en.wikipedia.org/wiki/
IPv4.
Your program must send packets in the following
Sample Output
When you run the program, identify each packet being sent either by number (packet 1, packet 2, etc.) or by
data length (data length 2, data length 4, etc.) and then display the server’s response. Here is one example
of how it might look:
$ java Ipv4Client
data length: 2
good
data length: 4
good
data length: 8
good
data length: 16
good
data length: 32
good
data length: 64
good
data length: 128
good
data length: 256
good
data length: 512
good
data length: 1024
good
data length: 2048
good
data length: 4096
good