Python Socket connection over 2 different networks - python

I know there are tons of questions like this but none of them helped me. I am trying to connect computer and vm that are on 2 different networks.
Server:
import socket
HOST = '0.0.0.0'
PORT = 1080
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen(5)
print("\n Listening on port " +str(PORT)+ ", waiting for client to connect...")
client_socket, (client_ip, client_port) = server_socket.accept()
print("[+] Client " +client_ip+ " connected!\n")
while True:
try:
command = raw_input(client_ip+ ">")
if(len(command.split()) != 0):
client_socket.send(command)
else:
continue
except Exception,e:
print("[-]Something went wrong")
continue
if(command == "stop"):
break
data = client_socket.recv(1024)
print(data + "\n")
client_socket.close()
As you see,i opened a server that listens on port 1080 and accepts all connections.I turned off the windows firewall and the SPI Firewall. I also forwarded the port 1080( nmap scan finds it and says its open).
Client:
import socket
import platform
HOST = "output of whatismyipaddress.com when run on server computer"
PORT = 1080 # port(same as on server.py)
connection_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
connection_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
connection_socket.connect((HOST, PORT))
print("\n[*] Connected to " +HOST+ " on port " +str(PORT)+ ".\n")
while True:
command = connection_socket.recv(1024)
split_command = command.split()
print("Received command : " +command)
if (command == "stop"):
break
elif (command == "info"):
connection_socket.send(("Info: " + str(tuple(platform.uname()))))
connection_socket.close()
So client is sending data to server and server is sending commands to client.
I assume client doesn't need to have any port forwarded.
The client(vm) was connected to Android HotSpot. The server was connected to router that had port forwarded. I've choose bridged connection for vm and connected my external wifi card for it.
Server started listening and client started. I get error that the server did not properly respond after period of time when trying to connect. I also tried connecting using default gateway but no success.
I am a little confused about it since Wikipedia says:
A default gateway in computer networking is the node that is assumed to know how to forward packets on to other networks. Typically, in a TCP/IP network, nodes such as servers, workstations and network devices each have a defined default route setting, (pointing to the default gateway), defining where to send packets for IP addresses for which they can determine no specific route.
Which I understand as it is used to communicate over 2 different networks?
Anyways, does anyone know how can I fix this issue and what am I doing wrong?

Related

Create a socket server using python, and access it from another network\country

How can I create a socket server, and access it from another network\country? I create a server using java. I want to connect the server from another network (like a hotel's wi-fi)
How can I do that?
My python server:
def start():
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((socket.gethostname(), 2201))
print("Waiting for connection...\n")
while True:
server.listen()
(client, (ipNum, portNum)) = server.accept()
message = str(client.recv(32).decode())
if(message != ""):
print("Client: " + message)
Command(message.lower())
print("Server: " + BackMessage)
else:
time.sleep(0.05)
start() # Start the server
Python client:
import socket
HOST = '127.0.0.1' # The server's hostname or IP address
PORT = 2001 # The port used by the server
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((HOST, PORT))
s.sendall(b'Hello, world')
data = s.recv(1024)
print('Received', repr(data))
It's not working when I switch connections only when I'm in the same network with the server. How can I make it work?
My reputation is not enough to add a comment, so I put an answer here.
If server locate in a local area network, it cannot be found be a client in another local area network.
You should put the server at the WAN(Wide Area Network) or use NAT(Network Address Translation) + nat traversal.

Python socket connection not working over Local Network

I'm trying to get two computers (my PC and my laptop) to communicate over the Local Network using the Socket module in python.
This is the Server side code running on my PC (connected via LAN):
import socket
HOST = '192.168.1.3' #local PC IP
print(HOST)
PORT = 8080 # Port to listen on (non-privileged ports are > 1023)
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
conn, addr = s.accept()
with conn:
print('Connected by', addr)
while True:
data = conn.recv(1024)
print(data)
if not data:
break
conn.sendall(data)
And this is the Client side code, running on my Laptop (connected over WiFi):
import socket
TCP_IP = '192.168.1.3'
TCP_PORT = 8080
BUFFER_SIZE = 1024
MESSAGE = b"Hello, World!"
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TCP_IP, TCP_PORT))
s.send(MESSAGE)
data = s.recv(BUFFER_SIZE)
s.close()
print("received data:", data)
The thing is: when I execute both codes, the Server side stays idle waiting for a connection and the Client side, after a while stops and returns the following timeout error:
Traceback (most recent call last):
File "C:\Users\...\client.py", line 13, in <module>
s.connect((TCP_IP, TCP_PORT))
TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond
I can't understand why it won't connect from another device in the same network while it works perfectly if I execute the Client code on the same machine as the Server, even if when I run netstat -an in the CMD I can see the computer listening on that port:
TCP 192.168.1.3:8080 0.0.0.0:0 LISTENING
I tough it had something to do with the port forwarding so I tried playing around with it but I'm having troubles with that too (the ports seem to remain closed).
I really don't know what to do next, if you have some advice or know something else I could try please reply.
It actually was a firewall problem, I just needed to disable the windows defender firewall for the local network and now everything is working fine
In Windows 10, I had to open the port I was using for the socket, and it worked for me.
Here is a link to the instructions.
You're listening and connecting to the same IP - you need to listen to the client's IP(or just any IP with the correct port number) on the server and connect to the server's IP on the client.
For example, if the client's IP is 1.2.3.4 and the server's is 1.2.3.5, then
# server side
s.bind(('1.2.3.4', 8080)) # CLIENT_IP = '1.2.3.4'; PORT = 8080
# can also be s.bind(('0.0.0.0', 8080)) if you want multiple clients to connect.
# client side
s.connect(('1.2.3.5', 8080)) # SERVER_IP = '1.2.3.5'; PORT = 8080

Python ConnectionRefusedError: [Errno 61] Connection refused

Ive seen similar questions but they I couldn't fix this error. Me and my friend are making a chat program but we keep getting the error
ConnectionRefusedError: [Errno 61] Connection refused
We are on different networks by the way.
Here is my code for the server
import socket
def socket_create():
try:
global host
global port
global s
host = ''
port = 9999
s = socket.socket()
except socket.error as msg:
print("Socket creation error" + str(msg))
#Wait for client, Connect socket and port
def socket_bind():
try:
global host
global port
global s
print("Binding socket to port: " + str(port))
s.bind((host, port))
s.listen(5)
except socket.error as msg:
print("Socket binding error" + str(msg) + "\n" + "Retrying...")
socket_bind
#Accept connections (Establishes connection with client) socket has to be listining
def socket_accept():
conn, address = s.accept()
print("Connection is established |" + " IP:" + str(address[0]) + "| port:" + str(address[1]))
chat_send(conn)
def chat_send(conn):
while True:
chat =input()
if len(str.encode(chat)) > 0:
conn.send(str.encode(chat))
client_response = str(conn.recv(1024), "utf-8")
print(client_response)
def main():
socket_create()
socket_bind()
socket_accept()
main()
And my client code
import socket
#connects to server
s = socket.socket()
host = '127.0.0.1'
port = 9999
s.connect((host, port))
#gets chat
while True:
data = s.recv(1024)
print (data[:].decode("utf-8"))
chat = input()
s.send(str.encode(chat))
This may not answer your original question, but I encountered this error and it was simply that I had not starting the server process first to listen to localhost (127.0.0.1) on the port I chose to test on. In order for the client to connect to localhost, a server must be listening on localhost.
'127.0.0.1' means local computer - so client connents with server on the same computer. Client have to use IP from server - like 192.168.0.1.
Check on server:
on Windows (in cmd.exe)
ipconfig
on Linux (in console)
ifconfig
But if you are in different networks then it may not work. ipconfig/ifconfig returns local IP (like 192.168.0.1) which is visible only in local network. Then you may need external IP and setting (redirections) on your and provider routers. External IP can be IP of your router or provider router. You can see your external IP when you visit pages like this http://httpbin.org/ip . But it can still need some work nad it be bigger problem.
You need simply to start server at first, and then run the client_code.
In VS Code i've opened 2 terminals. One for the server_code to be running While True, and the other one for the client_code
So this may not fix your question specifically but it fixed mine and it can help someone else I work with vscode and I use some extension that runs my code so when you want to run your server run it on your CMD or Terminal and run your client in vscode it helped me (maybe importat I work on mac so maybe spesific OS problem)
If you are connecting to a host:port that is open but there is no service bound to it you may see this IIRC. Eg with ssh you sometimes see this while attempting to connect to a server that is booting but sshd is not running.
This Code Not Valid For Chatting, you have to use unblocking sockets and select module or other async modules

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?

How to connect two computers on the same network using python

This is the server side program
import socket
s = socket.socket()
host = socket.gethostname()
port = 9077
s.bind((host,port))
s.listen(5)
while True:
c, addr = s.accept()
print("Connection accepted from " + repr(addr[1]))
c.send("Thank you for connecting")
c.close()
This is the client program
import socket
s = socket.socket()
host = socket.gethostname()
port = 9077
s.connect((host, port))
print s.recv(1024)
When i run these two programs on the same computer, it works perfectly.
But when i run the client and server programs in two different computers on the same network, the program doesn't work.
Can anyone please tell me how to send message from one computer to another on the same network.
This is the first time i'm doing any network programming. Any help would be appreciated
Thanks in advance
You are connecting from the client to the client's computer, or well attempting to, because you are using the client's hostname rather than the servers hostname/ip address.
So, to fix this change the line s.connect((host, port)) so that the host points to the servers ip address instead of the client's hostname.
You can find this by looking at your network settings on the server and doing the following:
host = "the ip found from the server's network settings"
host must be edited to the server's ip if the server is not the same computer.

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