Resolving connection problems

An installation might fail because the Domain Name System (DNS) server is unable to resolve system names or because the application server is not running.

Symptoms

IBM® InfoSphere® Information Server installation fails when the Domain Name System (DNS) is unable to resolve system names. The installation program returns an error message that is similar to the following message:
CDIIN2107E: Unable to validate the IBM InfoSphere Information Server user name name 
and password for host hostname at port port_number. The 
returned message is:
java.net.UnknownHostException: hostname.

Confirm that 1) WebSphere Application Server is running; 2) you entered the correct 
user name and password; 3) the port number is correct.

Causes

The communication between the installation computer and the application server on the services tier is not established. The following issues might cause this problem:
  • The connection to the application server uses the short host name.
  • The connection to the application server uses a host name that does not match the name that the computer had when the application server was installed.
  • The short host name does not map to the same IP address as the long host name.
  • The application server is not running.

Diagnosing the problem

When the services tier is installed on hostname.domain, use the following ping commands to test the connection to the short host name and to the long host name:
ping hostname 
ping hostname.domain

Resolving the problem

  1. Ensure that the application server is running.
  2. Ensure that the etc/hosts file is correctly configured with the short host name and long host name of the services tier computer.
  3. Ensure that all necessary ports are open among the client tier, engine tier, and services tier computers.
  4. Ensure that the host name that is used to access the services tier computer is the same name that the computer had when the application server was installed.
  5. Ensure that localhost and the computer host name are not both mapped to the loopback IP address. The IPv4 version of this address is 127.0.0.1 and the IPv6 version is ::1/128. Map only localhost to IP address 127.0.0.1. The following example shows an etc/hosts file where these entries are specified correctly:
    127.0.0.1 | ::1/128 localhost.localdomain localhost 
xx.xx.xx.xx | xx:xx::xx:xx machinelonghostname
machineshorthostname
    xx.xx.xx.xx | xx:xx::xx:xx is the unique IP address of the computer.
  6. If the engine tier or services tier was installed on a computer that has incorrectly configured host names, reinstall IBM InfoSphere Information Server.