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Informix Error -956: Client client-name is not in /etc/hosts.equiv on the remote host.

Cause and resolution

Client client-name is not in /etc/hosts.equiv on the remote host.

This operation cannot be completed because the specified remote computer does not recognize the name of the client computer (the local host, whose name the hostname command returns). Client names are normally recorded in the configuration file /etc/hosts.equiv. The rhosts file on the remote computer might also need modification. For more information on these files and the relation between them, try man rhosts on a UNIX system. See the remote host administrator to ensure that the client host name is specified in /etc/hosts.equiv file for the remote host. This message appears in versions prior to Version 6.0.

-956 Client client-name or user is not trusted by the database server.

The desired database server does not consider the client computer or your user ID trusted. Ask the system administrator to include the client computer as a trusted host and/or your user id as a trusted user in the /etc/hosts.equiv file on the server computer or in the .rhosts file in your home directory on the server computer. See the UNIX manual pages on HOSTS.EQUIV(5) for more information.

Alternatively, you can explicitly specify your user name and password in the USER clause of a CONNECT statement or in the .netrc file in your home directory on the client computer. See the IBM Informix Guide to SQL: Syntax for information on the CONNECT statement, and the UNIX manual pages regarding NETRC(5) for information on the .netrc file. This message appears with Version 6.0 and later.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-956 fires when the target database server doesn't consider the connecting client computer/user trusted — per the official guidance, this is a host/user-trust configuration gap, distinct from -954's host-recognition gap (this is about trust, not mere recognition) and from -950/-951's PAM/general user-not-known errors.

  1. The client computer not listed as a trusted host on the server, per the official guidance — via /etc/hosts.equiv on the server, or a per-user .rhosts file.
  2. The connecting user ID not listed as a trusted user, per the official guidance, in either of those same files.
  3. No explicit username/password supplied, per the official guidance's alternative — this trust-based mechanism can be bypassed entirely by specifying credentials directly.
Solutions / Resolution
  1. Ask the system administrator to include the client computer as a trusted host and/or your user ID as a trusted user, per the official guidance, in /etc/hosts.equiv on the server, or in .rhosts in your home directory on the server.
  2. Consult the UNIX manual pages on HOSTS.EQUIV(5) for more information, per the official guidance.
  3. Or explicitly specify your user name and password, per the official guidance, either in the USER clause of a CONNECT statement, or in .netrc in your home directory on the client computer — this avoids relying on host/user trust entirely.
Examples
Bypassing trust-based access with explicit credentials
CONNECT TO 'sales@remote_server' USER 'myusername' USING 'mypassword';
Diagnostic Checks
  1. Check /etc/hosts.equiv and .rhosts on the server for the client host/user.
  2. Consider switching to explicit credentials (CONNECT ... USER, or .netrc) if trust-based configuration isn't practical to maintain.
Related Errors / Related Topics
  • -950 — "User username is not known on the database server." A related authentication error, in the PAM-specific context.
  • -951 — "User username is not known on the database server." A related authentication error, the more general (Version 6.0+) user-ID mismatch case.
  • -954 — "Client is not known to remote host." A related but distinct error — mere host recognition (via /etc/hosts) rather than the trust configuration this error is about.

A host/user-trust gap — either fix the trust configuration on the server, or bypass it with explicit credentials via CONNECT ... USER or .netrc.