SQL30081N - ipclean and DB2

 SQL30081N A communication error has been detected. Communication protocol
being used: "*". Communication API being used: "*". Location where the error
was detected: "". Communication function detecting the error: "create_agent".
Protocol specific error code(s): "54", "*", "*". SQLSTATE=08001"

I checked the message queues and shared memory segments . This revealed a large amount of entries related to the instance.
I was attempting to do a "db2stop force" and this was hanging.
I cleared everything down with "ipclean" . This allowed the memory segments to be cleared.