Security

A step-by-step guide to creating and securing VLANs in the UniFi Network Console, including firewall rules to block inter-VLAN traffic and restrict console access.

The ID4262 error occurs when a SAML NameIdentifier uses the entity format but contains an invalid URI. Two resolution steps fix the issue within your identity provider configuration.

JDK 1.8.0u242 and later introduced Kerberos referral handling per RFC 6806, which can break Active Directory name canonicalization and produce a KRB_AP_ERR_MODIFIED error. This post walks through the two configuration fixes that resolve the issue.

A quick fix for the SSL Library Error 185090057 that appears when restarting Apache, caused by a malformed PEM certificate file. Learn how to validate and correct the certificate format to get your server back online.

A quick awk pipeline to pull wp-login.php access attempts from web server logs and flag IPs that exceed a threshold. Useful for spotting brute-force or scanning activity against WordPress sites.

Quick openssl commands to inspect a Certificate Signing Request and an issued X.509 certificate in human-readable form.