Service was restored and has been stable since approximately 6PM. The cause of the issue was a router failure at a major DNS provider. This disruption was not isolated to Columbia. The DNS provider has reported that they have addressed the root cause and consider the issue resolved. We apologize for any inconvenience this may cause and thank you for your patience. If you have any questions, please contact your support team. Faculty Support: 212-854-6097/ facsup@gsb.columbia.edu