DB2 Connect Quick Beginnings for UNIX**

Configuring TCP/IP on the Client

This section assumes that TCP/IP is functional on the client and server workstations. See Software Requirements for the communication protocol requirements for your platform. See Possible Client-to-Server Connectivity Scenarios for the supported communication protocols for your particular client and server.

To set up TCP/IP communications on a DB2 client, perform the following steps:

Step  1.	Identify and record parameter values.
Step  2.	Configure the client: Resolve the server's host address. Update the services file. Catalog a TCP/IP node. Catalog the database.
Step  3.	Test the connection between the client and server.

Due to the characteristics of the TCP/IP protocol, TCP/IP may not be immediately notified of the failure of a partner on another host. As a result, a client application accessing a remote DB2 server using TCP/IP, or the corresponding agent at the server, may sometimes appear to be hung. DB2 uses the TCP/IP SO_KEEPALIVE socket option to detect when there has been a failure and the TCP/IP connection has been broken. If you are experiencing problems with your TCP/IP connection, refer to the Troubleshooting Guide for information on how to adjust this parameter and other common TCP/IP problems.

Step 1. Identify and Record Parameter Values

As you proceed through the configuration steps, complete the Your Value column in the following table. You can fill in some of the values before you start configuring this protocol.

Table 22. TCP/IP Values Required at the Client

Parameter	Description	Sample Value	Your Value
Host Name Hostname (hostname) or IP address (ip_address)	Use the hostname or ip_address of the remote server workstation. To resolve this parameter: Enter the hostname command at the server to obtain the hostname. Contact your network administrator to obtain the ip_address or enter the ping hostname command. On UNIX systems, you can also use the DB2/bin/hostlookup hostname command. where DB2 is the directory where DB2 is installed.	serverhost or 9.21.15.235
Service Name Connection Service name (svcename) or Port number/Protocol (port_number/tcp)	Values required in the services file. The Connection Service name is an arbitrary local name that represents the connection port number (port_number) on the server. The port number must be the same as the port number that the svcename parameter maps to in the services file at the server. (The svcename parameter is located in the database manager configuration file on the server.) This value must not be in use by any other applications, and must be unique within the services file. Contact your database administrator for the values used to configure the server.	server1           3700/tcp
Node name (node_name)	A local alias, or nickname, that describes the node to which you are trying to connect. You can choose any name you want; however, all node name values within your local node directory must be unique.	db2node

Step 2. Configure the Client

The following steps configure the client to communicate with the server using TCP/IP. Replace the sample values with your worksheet values.

A. Resolve the Server's Host Address

If your network has a name server, or you are planning to directly specify the IP address (ip_address) of the server, skip this step and proceed to Step B. Update the Services File.

The client must know the IP address of the server to which it is attempting to establish communications. If a name server does not exist on your network, you may directly specify a hostname that maps to the IP address (ip_address) of the server in the local hosts file. See Table 23 for the location of the hosts file for your particular platform.

If you are planning on supporting a UNIX client that is using Network Information Services (NIS), and you are not using a name server on your network, you must update the hosts file located on your NIS master server.

Table 23. Location of the Local Hosts and Services Files

Platform	Location
OS/2	Specified by the etc environment variable. Enter the set etc command to determine the location of your local hosts or services files.
Windows NT or Windows 2000	Located in the winnt\system32\drivers\etc directory.
Windows 9x	Located in the windows directory.
UNIX	Located in the /etc directory.

Edit the client's hosts file and add an entry for the server's hostname. For example:

   9.21.15.235     serverhost   # host address for serverhost

where:

9.21.15.235

represents the ip_address

serverhost

represents the hostname

#

represents a comment describing the entry

If the server is not in the same domain as the client, you must provide a fully qualified domain name such as serverhost.vnet.ibm.com, where vnet.ibm.com is the domain name.

Step B. Update the Services File

If you are planning to catalog a TCP/IP node using a port number (port_number), skip this step and go to Step C. Catalog a TCP/IP Node.

Using a local text editor, add the Connection Service name and port number to the client's services file for TCP/IP support. For example:

   server1  3700/tcp  # DB2 connection service port

where:

server1

represents the Connection Service name

3700

represents the connection port number. The port number specified on the client must match the port number used on the server.

tcp

represents the communication protocol that you are using

#

represents a comment describing the entry

If you are planning on supporting a UNIX client that uses Network Information Services (NIS), you must update the services file located on your NIS master server.

The services file is located in the same directory as the local hosts file that you may have edited in A. Resolve the Server's Host Address.

See Table 23 for the location of the services file for your particular platform.

Step C. Catalog a TCP/IP Node

You must add an entry to the client's node directory to describe the remote node. This entry specifies the chosen alias (node_name), the hostname (or ip_address), and the svcename (or port_number) that the client will use to access the remote server.

To catalog a TCP/IP node, perform the following steps:

Step  1.	Log on to the system with a valid DB2 user ID. For more information, see Appendix D, Naming Rules. If you are adding a database to a system that has a DB2 Connect server product installed, log on to this system as a user with System Administrative (SYSADM) or System Controller (SYSCTRL) authority on the instance. For more information, see Working with the System Administrative Group. This restriction is controlled by the catalog_noauth database manager configuration parameter. For more information, refer to the Administration Guide.
Step  2.	If you are using a UNIX client, run the start-up script as follows: . INSTHOME/sqllib/db2profile (for bash, Bourne or Korn shell) source INSTHOME/sqllib/db2cshrc (for C shell) where INSTHOME is the home directory of the instance.
Step  3.	Catalog the node by entering the following commands: db2 "catalog tcpip node node_name remote [hostname|ip_address] server [svcename|port_number]" db2 terminate For example, to catalog the remote server serverhost on the node called db2node, using the service name server1, enter the following: db2 catalog tcpip node db2node remote serverhost server server1 db2 terminate To catalog a remote server with the IP address 9.21.15.235 on the node called db2node, using the port number 3700, enter the following: db2 catalog tcpip node db2node remote 9.21.15.235 server 3700 db2 terminate

If you need to change values that were set with the catalog node command, perform the following steps: Step  1. Run the uncatalog node command in the command line processor as follows: db2 uncatalog node node_name Step  2. Recatalog the node with the values that you want to use.

Step D. Catalog the Database

Before a client application can access a remote database, the database must be cataloged on the server node and on any client nodes that will connect to it. By default, when you create a database, it is automatically cataloged on the server with the database alias (database_alias) the same as the database name (database_name). The information in the database directory, along with the information in the node directory, is used on the client to establish a connection to the remote database.

To catalog a database on the client, perform the following steps:

Step  1.	Log on to the system with a valid DB2 user ID. For more information, see Appendix D, Naming Rules. If you are adding a database to a system that has a DB2 Connect server product installed, log on to this system as a user with System Administrative (SYSADM) or System Controller (SYSCTRL) authority on the instance. For more information, see Working with the System Administrative Group. This restriction is controlled by the catalog_noauth database manager configuration parameter. For more information, refer to the Administration Guide.
Step  2.	Fill in the Your Value column in the following worksheet. Table 24. Worksheet: Parameter Values for Cataloging Databases Parameter Description Sample Value Your Value Database name (database_name) The database alias (database_alias) of the remote database. When you create a database, it is automatically cataloged on the server with the database alias (database_alias) the same as the database name (database_name), unless specified otherwise. sample   Database alias (database_alias) An arbitrary local nickname for the remote database, on the client. If you do not provide one, the default is the same as the database name (database_name). The database alias is the name that you use when connecting to the host or AS/400 database server from the DB2 Connect server. tor1   Authentication (auth_value) The value of the authentication required by your enterprise. Please refer to the DB2 Connect User's Guide for more information on this parameter. DCS This means that the userid and password supplied are validated at the host or AS/400 only.   Node name (node_name) The name of the node directory entry that describes where the database resides. Use the same value for node name (node_name) that you used to catalog the node in the previous step. db2node
Step  3.	If you are using a UNIX client, run the start-up script as follows: . INSTHOME/sqllib/db2profile (for bash, Bourne or Korn shell) source INSTHOME/sqllib/db2cshrc (for C shell) where INSTHOME represents the home directory of the instance.
Step  4.	Catalog the database by entering the following commands: catalog database database_name as database_alias at node node_name authentication auth_type terminate For example, to catalog a remote database called sample so that it has the alias tor1, on the node db2node, enter the following commands: catalog database sample as tor1 at node db2node authentication dcs terminate If you need to change values that were set with the catalog database command, perform the following steps: Step  a. Run the uncatalog database command as follows: db2 uncatalog database database_alias Step  b. Recatalog the database with the value that you want to use.

Step 3. Test the Client-to-Server Connection

After configuring the client for communications, you will need to connect to a remote database to test the connection.

Step  1.	Start the database manager by entering the db2start command on the server (if it was not automatically started at boot time).
Step  2.	If you are using a UNIX client, run the start-up script as follows: . INSTHOME/sqllib/db2profile (for Bash, Bourne or Korn shell) source INSTHOME/sqllib/db2cshrc (for C shell) where INSTHOME represents the home directory of the instance.
Step  3.	Enter the following command on the client to connect the client to the remote database: db2 connect to database_alias user userid using password

The values for userid and password must be valid for the system on which they are authenticated. By default, authentication takes place on the server for a DB2 server and on the host or AS/400 machine for a DB2 Connect server.

If the connection is successful, you will get a message showing the name of the database to which you have connected. You are now able to retrieve data from that database. For example, to retrieve a list of all the table names listed in the system catalog table, enter the following SQL command in the Command Center or CLP:

     "select tabname from syscat.tables"

When you are finished using the database connection, enter the command reset command to end the database connection.

You are now ready to start using DB2. For more advanced topics, refer to the Administration Guide and the Installation and Configuration Supplement.

Troubleshooting the Client-to-Server Connection

If the connection fails, check the following items:

At the server:

1. The db2comm registry value includes the value tcpip.
   

   Check the settings for the db2comm registry value by entering the db2set DB2COMM command. For more information, refer to the Administration Guide.

2. The services file was updated correctly.
3. The service name (svcename) parameter was updated correctly in the database manager configuration file.
4. The security service was started. Enter the net start db2ntsecserver command (for Windows NT and Windows 2000 servers only).
5. The database was created and cataloged properly.
6. The database manager was stopped and started again (enter the db2stop and db2start commands on the server).

For more information on the db2diag.log file, refer to the Troubleshooting Guide.

At the client:

1. If used, the services and hosts files were updated correctly.
2. The node was cataloged with the correct hostname (hostname) or IP address (ip_address).
3. The port number matches, or the sevices name maps to, the port number used on the server.
4. The node name (node_name) that was specified in the database directory points to the correct entry in the node directory.
5. The database was cataloged properly, using the server's database alias (the database_alias that was cataloged when the database was created on the server), as the database name (database_name) on the client.

If the connection still fails after you verify these items, refer to the Troubleshooting Guide.