multiple tcp/ip stack

I created 3 different tcp/ip stacks in / (root dir) using io-net -i1 … so now i am going to use the particular stack in my application by setting SOCK environment variable before socket call.So it will do getenv(“SOCK”) in socket call and point to the specific prefixed stack.Now i want to know how can i check that this application is using specific prefixed stack.
Thanks in advance