Problem connecting to virtual machines using public IP address

Hey guys,

I have following setup 

VM1 redis, rabbitmq, open ports 6379, 5672

VM2 webapp, celery  

VM3 mysql open port 3306 

Now the issue is that sometimes webapp is not able to connect to all this open ports on the machine but other times it works fine.

I was able to replicate the issue with mysql-client and redis-cli so it doesn't look like issue.
This problem persists across VM communicaton.

Please help me mitigate/identify the problem here.

Rohitash