Raspberry Pi Client to Mac Server Error

Question

I am trying to make a Raspberry Pi processor communicate with my MacBook Pro using a C program. I have an Ethernet cable connected to both devices and a USB wireless adaptor for Wifi connection. Both the Mac and Pi are connected via the same Wifi network.

The C code establishes the Client-Server connection and this code can be found here:

Server: http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/server.c

Client: http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/client.c

The guide I am using is here: http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/socket.html

I placed the server.c file in one of my Mac's folders and the client.c file in a folder within the Raspberry Pi. After compiling both using 'gcc -o client client.c' and likewise server.c, I run the following on the MacBook Pro's Terminal:

./server 51717

Where 51717 is the port number I am using; the server code requires me to specify the port number. The client requires me to pass in my machine's hostname and port number. Therefore, I run the following from the Raspberry Pi's terminal:

./client localhost 51717

When running both ./server and ./client from my MacBook Pro, the program executes just fine. However, the error occurs when executing ./client from the Pi. This yields a: "Connection refused" error. I have tried looking up 'My Hostname' and inputted the value instead of putting 'localhost'. I also placed my IP address over 'localhost' and merely got a 'Connection timed out' error. I am not sure what else to input as my 'hostname' in order to make the connection work.

Answer 1

The issue was in fact that I needed to use the IP Address of the ethernet cable connected to the MacBook Pro. I found that by going to the WiFi button at the top of the screen, clicking 'Open Network Preferences', and then selecting the ethernet tab.