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Basical TCP/UDP client-server problem
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Basical TCP/UDP client-server problem
#1
Hi guys!
For an exam I have to code two simple client-server scripts in Python in order to study sockets and transport level protocols.
While they are runnin I have to run Wireshark and sniff the traffic, to study the segments

Basically, this is the code of the UDP part. It works and the message is received, but when I sniff the data, the segment isn't there and there's another port, why?

Client:
import socket
HOST = "127.0.0.1"
PORT = 33333
MSG = 'Prova protocollo UDP'
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.sendto(MSG.encode('utf-8'), (HOST, PORT))
Server:
import socket
PORT = 33333
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(("", PORT))
print ("Attesa sulla porta: ", PORT)
while 1:
data, addr = s.recvfrom(1024)
print (data.decode('utf-8'))
--------------


The same for TCP:

Client:
import socket

HOST = '' 
PORT = 36000
MSGRCVD = 'Messaggio ricevuto'

with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
with conn:
print ('Connesso a: ', addr)
while 1:
data = conn.recv(1024)
print(data.decode())
if not data: break
conn.sendall(MSGRCVD.encode())
Server:
import socket

HOST = "127.0.0.1"
PORT = 36000
MSG = 'Prova protocollo TCP'

with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((HOST, PORT))
s.send(MSG.encode())
data = s.recv(1024)
print("Ricevuto: ", data.decode())

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#2
what other port are you seeing? maybe there is other traffic going on at the same time.
Tradition is peer pressure from dead people

What do you call someone who speaks three languages? Trilingual. Two languages? Bilingual. One language? American.
Reply
#3
At TCP when you say a client, the code is for server and server part holds the client code  Cool
"As they say in Mexico 'dosvidaniya'. That makes two vidaniyas."
https://freedns.afraid.org
Reply
#4
yeah, it does look like client and server are reversed under tcp.
Tradition is peer pressure from dead people

What do you call someone who speaks three languages? Trilingual. Two languages? Bilingual. One language? American.
Reply


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