IPCheckr is a system for learning and testing subnetting. Students practice and get quick results, teachers manage classes, and sign-in can use your AD/LDAP. With GNS3 support, each user can launch their own lab safely.
Local: seeded admin admin / admin on first run (change immediately).
AD/LDAP: configurable host/port/SSL, bind or DN template, search base, username attribute, and group DNs for teacher/student role mapping. Switch auth mode in Admin -> Settings.