http://db2commerce.com/2011/04/14/how-to-catalog-a-db2-database/
How to catalog a db2 database
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1) Catalog the node
db2 catalog tcpip node <NODENAME> remote <REMOTE> server <PORT>
example: db2 catalog tcpip node prod_ecom remote servername.domain.com server 50001
2) Catalog the database
db2 catalog database <database_name> at node <node_name>
example: db2 catalog database wcs_prod at node prod_ecom
3) Refresh directory
db2 terminate