Can't connect to python server on LAN

Question

So I have this python server which just returns the uppercase sentence which came as a input:

from socket import *
serverPort = 12000
serverSocket = socket(AF_INET, SOCK_DGRAM)
serverSocket.bind(('192.168.1.2', serverPort))
print "The server is ready to receive on port: {}".format(serverPort)
while 1:
    message, clientAddress = serverSocket.recvfrom(2048)
    print clientAddress, message
    modifiedMessage = message.upper()
    serverSocket.sendto(modifiedMessage, clientAddress)

From this client:

from socket import *

serverName = "192.168.1.3"
serverPort = 12000
clientSocket = socket(AF_INET, SOCK_DGRAM)
message = raw_input("Input lowercase sentence:")
clientSocket.sendto(message,(serverName, serverPort))
modifiedMessage, serverAddress = clientSocket.recvfrom(2048)
print modifiedMessage
clientSocket.close()

Everything works as expected on localhost but when I execute server.py on one machine and run client.py on another machine the client is unable to contact server.py.
Furthermore I can't even connect to server.py via telnet on the same machine where server.py is running) Here's the traceback:

Connecting To 192.168.1.2...Could not open connection to the host, on port 12000: Connect failed 

Now I sniffed some packets using Wireshark and surprisingly, the protocol against this packet was LLC instead of UDP and the data field was:

Data: 74:5f:32:20:61:6e:64:72:6f:69:64
[Length: 11]

I apologize if the difference is trivial, but I have just started socket programming and it's bugging me.

Answer 1

Firstly, SOCK_DGRAM is UDP so you won't be able to use telnet because it's TCP only.

The packets are UDP. I expect that wireshark is just mistaking them for LLC because of the port 12000 (LLC runs on top of UDP I believe).

It looks like this isn't working because you've set serverName to .3 in the client script but the server is listening on .2.

I'll also just ignore the camel casing in Python ;)