How-To

A quick reference for diagnosing Kerberos authentication failures in Active Directory, covering the lockout state machine and the specific error codes (5be, 775, 18) that indicate revoked credentials or a locked account.

Learn how to check and interpret the kernel entropy pool on Linux, why low entropy can slow down SSL handshakes and SSH sessions, and what to do when the pool runs dry.

A quick reference for verifying AES-NI hardware acceleration across Java, OpenSSL, and the CPU itself. Includes benchmark commands to confirm the instruction set is actually being used.

A quick procedure for resolving Cloudera Manager agent failures caused by corrupted system alternatives entries, including the exact commands to stop the agent, purge stale alternatives, and restart cleanly.

When hostname -f returns a short name instead of a fully qualified domain name, the issue usually traces back to the HOSTNAME variable in /etc/sysconfig/network or a misconfigured /etc/hosts entry. Understanding the difference between the gethostname and gethostbyname system calls makes the fix straightforward.

Kerberos authentication failures can be tricky to diagnose without detailed logging. This guide walks you through enabling Kerberos event logging on a Windows machine via the registry so you can capture authentication events in the system log.