Outage category: Blackboard
Location: Onlline
Status: Closed
Resolved Alert:
Initial Symptoms
Reports to Support Center
Root Cause Analysis
Cause
On April 20th, Anthology’s DNS servers experienced a targeted and excessive amount of DNS requests which was intended to deny servicing DNS requests. DNS servers became overwhelmed and unable to service requests.
On April 25th, a change was executed to enhance our DNS services to prevent DDoS events like the one that took place on 4/20. This change was not successful which propagated incorrect DNS information across the internet. The change was rolled back but DNS is a pull- based request and took time to propagate the correction across the internet.
Resolution
Resolution
Some users needed to flush their DNS cache or contact their internet provider to flush at ISP level.
Prevention
Anthology fixed and re-executed the upgrade to DNS services to prevent issues like the one experienced on 4/20.