MPI run on external network

Question

I'm new to MPI and I wrote a program to calculate large factorials over multiple processors. I tested the program on my local network with only 2 machine. ie. a laptop and my PC and its working perfectly.

Now I am trying to run the program over the internet on my friend's PC. Everything is installed perfectly. I already configure the router for port forwarding and I can ssh with to a user account.

I'm using mpicc to compile the program and it works and i also successfully copied the executable file to the external machine through scp . My problem is when i run the command mpirun -hostfile hostlist -np 2 fname . the process is stucked and i get only a blinking cursor on the terminal.

can someone explain me why this is happening? Thanks.

Answer 1

As soon as you didn't provide any code snippet,

I'll just list what may be the reason, probably there are others too, the best way will be that you debug your code, and see where it is stuck

The reasons can be several

1. Code issue, wrong handling of special cases

2. Network issue, wrong configuration for a specific port, firewall configuration etc.

3. etc