Names that you need from the remote systems

If you plan to have your Db2 subsystem request data from other systems, you need the LU names and location names for those serving systems.

Location names and LU names: When you populate the communications database (CDB) in the local Db2, you must know the location names (or DRDA RDBNAMs) and LU names of remote servers. The remote servers are the systems from which this Db2 system is to request data. The local Db2 system does not need location names of requesters. However, you need to know the LU names of the requesters if you intend to change default communication options.

Db2 does not receive DRDA RDBNAM from requesters other than Db2 for z/OS. If Db2 does not have an RDBNAM, it displays LU names in messages, display output, and trace output. To help you distinguish between location names and LU names in those cases, the LU name is enclosed in less-than (<) and greater-than (>) brackets.

When your systems begin communicating, you and others involved in working with distributed systems need to be aware of the LU name to DRDA RDBNAM mappings. When you have obtained the necessary names, enter them in the CDB.

Transaction program names (TPNs): If a server is not a Db2 for z/OS, it might have an additional name that uniquely identifies it. In LU 6.2, this is known as a transaction program name (TPN), and can be 1–64 characters long. When a Db2 for z/OS subsystem communicates with other Db2 for z/OS subsystems, you do not need to supply TPN values. The Db2 subsystems automatically choose the correct TPN values.

When a TPN is necessary: You might need to supply TPN values when a Db2 subsystem requests data from a server that is not a Db2 for z/OS subsystem. For cases where the server does not accept the default TPN for DRDA access, enter into your CDB the TPN chosen by that server. For Db2 for VM, for example, the TPN is the SQL database machine ID.

TPN values accepted by Db2 for z/OS: A requester that is not Db2 for z/OS must use either the TPN name X'07F6C4C2' or DB2DRDA, which are the only values Db2 recognizes when it accepts a request from another system. Some requesters enter the TPN as two separate fields: a 1-byte prefix (X'07') and a 3-byte suffix ('6DB').