Dear all ,
I am getting the following error while connecting from any one of my client,s CONTROL CENTER (if I am cataloging from command prompt there is no error) to db2 server

SQL30081N A communication error has been detected. Communication protocol being used: "TCP/IP". Communication API
being used: "SOCKETS". Location where the error was detected: "192.168.100.47". Communication function detecting the
error: "connect". Protocol specific error code(s): "10061", "*", "*". SQLSTATE=08001

initially they are working fine, but since 3 to 4 days i am getting this problem

my client details : windows, db2 v9.1(for all clients)
server details : linux db2 8.2
I already set db2comm= TCPIP
i found somewhere the port must be UNUSED, what is the meaning of that?
In service file also I found port details currectly
telnet also working fine
1Q)I restarted the db2 server , the instance is started but with an error SQL1063, to over come this is whether I have to run db2licm –a (whether I have to provide licence from outside disk, can I find with in the server??? But same error showing since 2 to 3 years but there is no issue till now)
2Q)I think I have to work on DAS(database administrator server)
How can I check whether db2admin is on or not??
Pls let me know how AUTHENTICATION (dbm cfg parameter) will play key roll???
How I have to set this for AUTHENTICATION for db2 admin, db2 server and client???

The AUTHENTICATION for db2 admin is SYSTEM_ENCRYPT
The AUTHENTICATION for db2 server is SYSTEM
The AUTHENTICATION for db2 client is SYSTEM

In db2 server svcename (dbm cfg parameter) is set to port number instead of name. I think it wont be problem.

Other then above points I am missing any important thing.

Pls help me out…………………..

The following error I am getting while using control centre