NetWorker: ERROR Authentication failed, user 'default/DOMAIN.com/account', error: Authentication service is unavailable

Summary: Intermittent authentication issues: ERROR Authentication failed, user 'default/DOMAIN.com/account', error: Authentication service is unavailable.

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Symptoms

NetWorker is integrated with external authentication. 
AD/LDAP users intermittently observe login failures. Local NetWorker accounts (for example the default Administrator account) do not observe any authentication issues.

The NetWorker authentication (authc) server reports the following in the authc-server-audit.log:
Linux: /nsr/authc/logs/authc-server-audit.log
Windows: C:\Program Files\EMC NetWorker\nsr\authc-server\tomcat\logs\authc-server-audit.log 
2023-11-02T08:12:39.288+0100 INFO Local authentication failed, incorrect username/password
2023-11-02T08:14:50.235+0100 ERROR Authentication failed, user 'default/DOMAIN.com/account', error: Authentication service is unavailable
2023-11-02T08:14:50.235+0100 INFO Authentication failed, user 'default/DOMAIN.com/account', error: Authentication service is unavailable
2023-11-02T08:15:57.139+0100 INFO Local authentication failed, incorrect username/password
2023-11-02T08:17:38.028+0100 INFO Anonymous access
2023-11-02T08:17:38.031+0100 INFO Permission allowed, user 'anonymous' has 'EVERYONE_CONTROL' privilege to read this resource - Version
2023-11-02T08:17:38.545+0100 INFO User with id '1021' has PasswordNeverExpires flag set to true
2023-11-02T08:17:38.546+0100 INFO Authentication is successful, user 'username'
The error reports an incorrect username/password; however, the issue only occurs intermittently, suggesting the credentials are correct.

Cause

As the issue only appears on external users (AD/LDAP), the issue is believed to be occurring outside of NetWorker. Specific causes can vary.

Resolution

This issue must be investigated by the network and domain administrators.

Check the Domain Name System (DNS) resolution between the NetWorker server and AD server:

Verify that the NetWorker Authentication server is not observing high latency or communication issues with the AD server:
NOTE: The default AD/LDAP port is 389. If integration is using LDAPS (SSL), the default port is 636.
 

Affected Products

NetWorker Family, NetWorker, NetWorker Series
Article Properties
Article Number: 000223465
Article Type: Solution
Last Modified: 22 Oct 2025
Version:  2
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