Build, test, and debug regular expressions
Matches specific ESET Secure Authentication Provisioning Server DNS hostnames. Captures domains like ecp.eset.systems, esa.eset.com, m.esa.eset.com, and numbered host variants (h1-esa01-04, h3-esa2-01-04-v). Useful for network security policies, firewall rules, or DNS filtering to identify legitimate ESET authentication infrastructure.