16.2.2 Diagnosing Client Problems

Verify at least one of the following statements. This will help you decide if it is a client problem.

  • The database server passed a loopback test, showing the connection worked.

  • Other computers connect using Oracle Net Services to the same database.

  • Connections from this workstation worked before making changes on this computer, such as the installation of a new product or modification to the network configuration.

The following procedure describes how to perform diagnostics on the client:

  1. Check that you have installed the same protocol support that was installed on the database server.

    On Linux and UNIX platforms you can use the ADAPTERS utility to verify protocol support. On the database server, run the following command from the ORACLE_HOME/bin directory to display the protocol support, naming methods, and security options linked with the oracle executable: 

    adapters ./oracle

    The adapters utility displays output similar to the following: 

    Installed Oracle Net transport protocols are:

    IPC
    BEQ
    TCP/IP
    SSL
    RAW
    SDP/IB

Installed Oracle Net naming methods are:

    Local Naming (tnsnames.ora)
    Oracle Directory Naming
    Oracle Host Naming
    NIS Naming

Installed Oracle Advanced Security options are:

    RC4 40-bit encryption
    RC4 56-bit encryption
    RC4 128-bit encryption
    RC4 256-bit encryption
    DES40 40-bit encryption
    DES 56-bit encryption
    3DES 112-bit encryption
    3DES 168-bit encryption
    AES 128-bit encryption
    AES 192-bit encryption
    AES 256-bit encryption
    MD5 crypto-checksumming
    SHA crypto-checksumming (for FIPS)
    SHA-1 crypto-checksumming
    Kerberos v5 authentication
    RADIUS authentication

    On the client, run the adapters command from the ORACLE_HOME/bin directory to display the configured Oracle protocol support, naming methods, and security options. The ADAPTERS utility displays output similar to the following: 

    Installed Oracle Net transport protocols are:

    IPC
    BEQ
    TCP/IP
    SSL
    RAW
    SDP/IB
    Exadirect

Installed Oracle Net naming methods are:

    Local Naming (tnsnames.ora)
    Oracle Directory Naming
    Oracle Host Naming
   
Installed Oracle Advanced Security options are:

    RC4 40-bit encryption
    RC4 56-bit encryption
    RC4 128-bit encryption
    RC4 256-bit encryption
    DES40 40-bit encryption
    DES 56-bit encryption
    3DES 112-bit encryption
    3DES 168-bit encryption
    AES 128-bit encryption
    AES 192-bit encryption
    AES 256-bit encryption
    MD5 crypto-checksumming
    SHA-1 crypto-checksumming
    Kerberos v5 authentication
    RADIUS authentication

    Note:

    • The DES, DES40, 3DES 112, 3DES 168, RC4 40, RC4 56, RC4 128, RC4 256, and MD5 algorithms are deprecated in this release.

      To transition your Oracle Database environment to use stronger algorithms, download and install the patch described in My Oracle Support note 2118136.2.

    • RAW is an internal protocol used by Oracle Net.

    See Also:

    Oracle Database Administrator's Reference for additional information about the adapters utility

  2. Check base connectivity for underlying network transport. Oracle Net technology depends on the underlying network for a successful connection.

    Table 16-7 Verify Base Connectivity for Network Transport

    Protocol Verify that you can...

    TCP/IP

    Use terminal emulation or file transfer utilities, (PING, FTP, TELNET) from the client to the database server.

    Named Pipes

    • See other computers or servers on the Microsoft network.

    • Ensure that you are able to share drives within the network.

  3. Ensure that the Oracle Net foundation layer and the appropriate Oracle protocol support are present by verifying that all Oracle Net Services software has been installed for the client.

  4. Ensure that the client computer has the tnsnames.ora and the sqlnet.ora files in the correct locations.

    See Also:

    "Using Localized Management"

    If any other working client computers are connecting to the selected Oracle Database, then back up your existing files and copy both the working tnsnames.ora and sqlnet.ora files from the working client computer to the non-working clients. This eliminates the possibility of errors in the files.

  5. Test the Oracle Net foundation layer. You can test using the following command to connect to SQL*Plus:

    SQLPLUS user/password@connect_string

    Note:

    Do not use the TNSPING utility. The TNSPING utility works like the TCP/IP ping utility and does not create and open a socket, nor does it connect with the listener. It only shows that the listener is present on the database server.

  6. If the connection still fails, then do the following:

    1. Use tracing, as described in section "Tracing Error Information for Oracle Net Services".

    2. Check the Oracle Support Services website for a specific diagnostics bulletin on the error received.

    3. Contact Oracle Support Services.

Parent topic: Diagnosing Oracle Net Services