To be able to use db2 connect from client, there are few configuration steps to be followed as mentioned here:
on DB2 Server
db2set DB2COMM=tcpip
update database manager configuration using svcename 50000
db2stop
db2start
on Client Side
db2 UNCATALOG DATABASE db_name
db2 UNCATALOG DCS DATABASE db_name
db2 UNCATALOG NODE server_name
db2 CATALOG TCPIP NODE server_name REMOTE server_name SERVER 50000 REMOTE_INSTANCE DB2 SYSTEM server_name OSTYPE AIX
db2 CATALOG DCS DATABASE db_name AS db_name
db2 CATALOG DATABASE db_name AS db_name AT NODE server_name AUTHENTICATION DCS
$ db2 connect to db_name user user_name using password
Database Connection Information
Database server = DB2/AIX64 9.1.6
SQL authorization ID = user_name
Local database alias = db_name
