Testing TCP Client on Ubuntu VM from Android Mobile on Ethernet

Gopi

6/13/23, 2:37 PM

I am developing a TCP Application. My administrator has blocked TCP listening on my Windows PC. So, I am using an Ubuntu 20.04 VM on the virtual box for developing and testing my TCP server application.

I have tested my TCP Application server with the client from localhost. However, I need to test from the actual client system. In my case, it is an embedded system like Android Phone.

Before testing my actual TCP application, I am trying to test the setup with tools as below:

#On ubuntu VM to run sample TCP server ncat -l 9090 -k -c 'xargs -n1 echo'

#On Android phone, I am using an app from the play store called TCP/UDP TEST TOOL

 ___________________________________
|   _______________________         |
|  |  TCP_Server:9090      |        |
|  |   Ubuntu VM           |        |                                     ________________
|  | (Bridge iface)        | (iface)| <Ethernet Cable>                   |                |
|  | IP: 192.168.66.11/24  |        |   |-> <Ethernet to USB-C covertor> | Android Mobile |
|  |_______________________|        |                                    |________________|
|                                   |                               IP: 192.168.66.12/24               
| Win 10 PC(IP: 192.168.66.50)      |                               GW: 192.168.66.11
|___________________________________|

The problem is, the Android phone is unable to ping and connect to the TCP server on Ubuntu VM, But the reverse s working; Ubuntu VM could able to ping the Android phone and able to connect to a sample TCP service on Android Phone.

I connect my Ubuntu VM (bridged wifi interface) and Android phone to a Wifi router; The TCP client-server communication is working fine wherever I run client and server.

I have checked firewall rules on Ubuntu VM, they were empty with ACCEPT policy for Input, Forward, Output chains.

From Win 10 Host OS, I could ping IP of both VM(192.168.66.11) and Android Phones(192.168.66.12)!

0 + 0

virtualbox

usb

network-bridge

sockets

David

6/13/23, 4:44 PM

Windows could able to ping both VM and Android Phones! What does this mean?

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Testing TCP Client on Ubuntu VM from Android Mobile on Ethernet

TH: ทดสอบ TCP Client บน Ubuntu VM จาก Android Mobile บน Ethernet

RO: Testarea clientului TCP pe Ubuntu VM de pe Android Mobile pe Ethernet

RU: Тестирование TCP-клиента на виртуальной машине Ubuntu с Android Mobile через Ethernet

VI: Kiểm tra TCP Client trên Ubuntu VM từ Android Mobile trên Ethernet

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