Develop Reference

Raspberry Pi server with Scoket/Python problem

I'm trying to create a simple web server with Raspberry Pi 4 - Model B using sockets in Python.
The problem is that I can request from any web browser in my loclal network and the server works, but when I try to request from an external network (different IP of the Raspberry Pi server) nothing happens.
I have read a bit about it and in most of cases the problem was solved writing as IP "0.0.0.0" in the bind method of the server code, but it didn't worked for me... Is there any other error?? please help me, I'm stuck
import socket #Importa la libreria Socket
message = "Hello Internet, I'm Here!!"#Message to send to the client
IP = "0.0.0.0" #Listens to any IP client
PORT = 2020 #Server Port
mySocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mySocket.bind((IP, PORT))
mySocket.listen(5)
while True:
print("\n"+"Waiting for a client...")
client1, client1_addr = mySocket.accept()
print("Got a request from client")
request = client1.recv(1024)
print("Sending Response...")
http_response = b'HTTP/1.1 200 OK\r\n\r\n'
client1.send(http_response)
byts = bytes(message, 'utf-8')
client1.send(byts) #Envia el mensaje al cliente
print("Response sent!!!")
client1.close()
mySocket.close()

UDP socket can't receive data from server: python

I am establishing a TFTP connection using UDP.
My client is able to successfully send a request to server
cSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
cSocket.bind(('', clientPort))
cSocket.settimeout(1)
cSocket.sendto(key, (Serverip, 69))
And server is able to receive it
serverSock.bind((serverIP, 69))
request, clientIP = serverSock.recvfrom(1024)
Now from anthother port server is responding back to client with an acknowledgement
aSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
aSocket.settimeout(0.1)
aSocket.sendto(byteArray, (clientIP, clientPort))
From Wireshark I am able to see the acknoledgement send from server but
data, addr = cSocket.recvfrom(1024)
Leads to a timeout exception. Where did i went wrong?

Python3 server not responding to client request

I am setting up a basic python application that will listen for UDP packets at a specific port.
I am using an example code found online to begin to familiarize myself with UDP and socket connection.
When I invoke client.py and then server.py - the server does not respond and the terminal remains idle - any solutions for this problem? Below is the basic code I am working with
Client.py
import socket
UDP_IP_ADDRESS = "127.0.0.1"
UDP_PORT_NO = 6789
Message = b"Hello, Server"
clientSock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
clientSock.sendto(Message, (UDP_IP_ADDRESS, UDP_PORT_NO))
Server.py
import socket
UDP_IP_ADDRESS = "127.0.0.1"
UDP_PORT_NO = 6789
serverSock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
serverSock.bind((UDP_IP_ADDRESS, UDP_PORT_NO))
while True:
#data, addr = serverSock.recvfrom(1024)
data, addr = serverSock.recvfrom(1024)
print ("Message: ", data)

When I invoke client.py and then server.py
Well that's your problem--by invoking the client which sends, then later invoking the server which receives, you are preventing the two from communicating. The server needs to be running at the moment the client sends.

Python 3.6.1 why don't I receive UDP packets

I have a server where I have a script which sends UDP packets to my ip address and I have a client script on my PC that receives UDP packets.
#python3.6.1
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(('myip', 49999))
data, address = sock.recvfrom(100)
print('Received {}'.format(data.decode('ascii')))
On the server side my scripts connects to ('myip', 49999) and starts sending packets.
I took my ip from ip4.me i tried to bind my socket to '0.0.0.0' too and i tried other ports nothing seems to work.

If that is the server script, i guess it should have a while loop in it:
while True:
data, address = sock.recvfrom(100)
print('Received {}'.format(data.decode('ascii')))

communication between two computers via Python socket in a LAN failed

Two computers in a LAN connecting to a wireless router, one IP address is 192.168.1.106 (server), the other one is 192.168.1.107 (client), the gateway on both computer is 192.168.1.1 (the router itself).
The two computer can ping each in two directions which means there should be no problem with routing and the router itself. But I failed when I tried to use Python UDP socket, the server cannot get any information from the client, and same happened when I change the ip address. (But it works fine when server and client are on a same computer using local ip address, so the code is should be ok)
I am using the following code:
server:
import socket
address = ('192.168.1.106', 5678) # the server listening on address 192.168.1.106
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(address)
while True:
data, addr = s.recvfrom(2048)
if data == "empty":
print "no data from client"
else:
print "received:", data, "from", addr
s.close()
client:
import socket
address = ('192.168.1.106', 5678) # the client send to address 192.168.1.106
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
while True:
msg = raw_input()
if not msg:
msg = "empty"
s.sendto(msg, address)
s.close()

Did you open the UDP port on the firewall on both comoutera?